When may you use your cell phone while driving?

Answer: C — Under certain conditions

Using your cell phone while driving is typically considered dangerous and often illegal. Option A states that you can use your phone when parked, which is correct and the safest option. Option B states that you can use your phone when reporting an emergency, which is also correct as it is important to prioritize safety in emergency situations. Option D states that you should never use your phone while driving, which is also true in most cases. However, option C states that you can use your phone while driving under certain conditions, such as using hands-free technology or while at a stoplight. This option acknowledges that there may be specific situations where using a cell phone while driving may be necessary, but it is still important to exercise caution and prioritize safety. Therefore, option C is the most comprehensive and accurate answer.