Questions: You attempt to turn on your car, but it does not work. Which of these is a hypothesis? My car isn't turning on because the battery is dead. I drove a really far distance yesterday in my car. I should get a new car. Why doesn't my car work?

The answer is the first one: My car isn't turning on because the battery is dead.

Explanation for each option:

1. "My car isn't turning on because the battery is dead." - This is a hypothesis because it provides a specific, testable explanation for why the car isn't turning on.
2. "I drove a really far distance yesterday in my car." - This is a statement of fact or observation, not a hypothesis.
3. "I should get a new car." - This is a suggestion or recommendation, not a hypothesis.
4. "Why doesn't my car work?" - This is a question, not a hypothesis.

Summary: The hypothesis among the given options is "My car isn't turning on because the battery is dead." This statement offers a potential explanation that can be tested to determine if it is the cause of the problem.