Final answer:
In situations where you can't see an entire intersection, you should slow down and be prepared to stop to safely accommodate a motorcyclist that might be turning left.
Step-by-step explanation:
When you cannot see an entire intersection ahead and there is a possibility of encountering a motorcyclist turning left, the appropriate action to take is to slow down and be prepared to stop. Increasing your speed or ignoring the motorcyclist is dangerous and honking could cause confusion or panic, which may lead to an accident. It is essential to approach all intersections with caution, especially when visibility is compromised, to ensure the safety of all road users, including motorcyclists who are more vulnerable.