Practice questions on any subject: the prompt for ChatGPT, Claude and Gemini

You are writing exam-style multiple-choice practice questions for me, a student revising from my own course materials.
Subject and topics: [REPLACE THIS with your subject and a list of the topics you want questions on, for example "Pharmacology: drug absorption, drug metabolism, adverse reactions"]

Write 20 questions. Each must be a standalone multiple-choice question that can be answered from its own stem and options, with exactly the right answer(s) marked and nothing ambiguous.

Set each question's `topic` to one of the topics I listed above, spelled exactly the same way every time, and `subtopic` (optional) to something more specific within it.

Spread the questions across the topics so that every topic gets some.

Give each question between 2 and 6 options. Options are plain text without letter prefixes (DoMcq labels them A, B, C… by position); make them similar in length and form so the right one does not stand out.
Most questions have one correct option. Where the real exam uses multiple-answer items, write some with two or more correct options: the stem must then say how many to choose ("Choose TWO.", "Choose THREE."), `answer` lists every correct letter in ascending order ("BD"), and at least one option must be incorrect.
Avoid "all of the above", "none of the above" and "both A and B" style options.

Keep each stem self-contained (any scenario the question needs is in the stem), concrete and free of trick wording. Do not refer to other questions, images, tables or exhibits.

Mix the difficulty: about 6 easy, 10 medium and 4 hard, and set each question's `difficulty` to "easy", "medium" or "hard" accordingly.

In `explanation`, say in two to four sentences why the correct answer is correct, in a way that teaches the underlying point, not just restates the option.

In `source`, give a short reference I can check in my own study materials (a syllabus topic, a chapter or section name, a learning objective, or a standard's clause), at most 200 characters; never invent a page number or a quotation.

Leave out `rationales` and `id`.

Before you answer, check your own work: no two questions ask the same thing; no question gives away another's answer; the correct option sits in a different position from one question to the next (never always the same letter); every `answer` letter exists for that question; the correct option is correct according to the current official material, not folklore; facts are accurate. Fix anything you find.

Output the whole set as one JSON object in the `domcq/1` format (schema: https://domcq.com/schema/v1; this is the import format of https://domcq.com):

```json
{
  "format": "domcq/1",
  "set": "[a short name for this set]",
  "questions": [
    {
      "stem": "[the question, 10–2000 characters]",
      "options": [
        "[option 1]",
        "[option 2]",
        "[option 3]",
        "[option 4]"
      ],
      "answer": "B",
      "explanation": "[why the correct answer is correct, 1–3000 characters]",
      "topic": "[topic name]",
      "subtopic": "[optional, more specific]",
      "difficulty": "medium",
      "source": "[a reference I can check]"
    }
  ]
}
```

Rules the import enforces: `format` is exactly "domcq/1"; `set` is 1–120 characters; `questions` holds all 20; each question has exactly the fields shown (no others); `stem` is 10–2000 characters and each option 1–500; `options` are all different; `answer` uses capital letters A–F naming options by position, in ascending order, never every option; `explanation` (1–3000 characters) and `topic` are required; `subtopic` (up to 120 characters), `difficulty` ("easy", "medium" or "hard") and `source` (up to 200 characters) are optional. Use plain double quotes in JSON strings (escape any inside text as \"), no trailing commas, no comments.

Reply with the JSON object inside a single ```json code fence and nothing else: no introduction, no commentary, no notes after it. If the set is long, keep going until every question is written and the JSON is complete and closed.