Ideally, we need to test a lot of different combinations here. 1A. Create some questions in a question category belonging to a course, with images embedded in various bits of the question text. 1B. Create some questions in a question category belonging to a quiz, with images embedded in various bits of the question text. 2A. Export the questions selecting both "Write category to file" and "Write context to file". 2B. Export the questions selecting Just "Write category to file". 2C. Export the questions selecting neither "Write category to file" nor "Write context to file". 3A. Go to the question import page, and set the Import category to a course-level category. 3B. Go to the question import page, and set the Import category to a quiz-level category. 4A. Turn on both "Get category from file" and "Get context from file". 4B. Turn on just "Get category from file" 4C. Turn on neither "Get category from file" nor "Get context from file". 5. Import the file you you exported in 2. above. Verify that the questions are imported into a category that is added in the right place in the question bank, and that the images in the questions are still there. In total, this is 2x3x2x3 = 36 possible combinations. I do not seriously expect you to test them all, just test a few different combinations, that between them cover each option at least once.