Question

you try to start your car, but it does not start. which of these is a hypothesis? what is wrong with my car? my car is too old to function properly. my cars electrical circuit is damaged.

Explanation:

A hypothesis is a proposed explanation for a phenomenon. "What is wrong with my car?" is a question, not an explanation. "My car is too old to function properly" is a rather broad and general statement. "My car's electrical circuit is damaged" is a specific proposed explanation for why the car won't start.

Answer:

My car's electrical circuit is damaged.