Final answer:
The right time to turn on the turn signal when entering a freeway is as you reach the entrance ramp so other drivers can see your intention to merge. It's crucial for safety and usually required by law.
Step-by-step explanation:
When entering a freeway, the right time to turn on the turn signal is answer choice B: When the motorcyclist reaches the entrance ramp and the freeway traffic is able to see the turn signal. This allows other drivers on the freeway to be aware of the motorcyclist's intention to merge into traffic. It's important to use the signal early enough to give other drivers ample time to react, which ensures safety for everyone on the road. Remember, whether you are driving a car or riding a motorcycle, using your turn signals when changing lanes or entering a highway is not just courteous but also a legal requirement in many areas.