Final answer:
Goggles can be removed during an experiment only after receiving permission from the instructor, ensuring that it is safe to do so.
Step-by-step explanation:
You can take your goggles off during an experiment only after receiving permission from the instructor. Personal discomfort does not warrant removing safety equipment during an experiment, and it is crucial to wait for the instructor's guidance to ensure that all procedures have been safely concluded and that there is no residual risk of exposure to chemicals or reactions. Therefore, the correct answer to the question of when you can remove your goggles during an experiment is c) Only after receiving permission from the instructor.