根据所给句子，选择最佳的应答语。每个选项只能用一次。

( )1. Why are you late for class?

( )2. If you don't get enough sleep, you'll be exhausted in class.

( )3. Have you ever been an April Fool, Maria?

( )4. Hi, Michael. You look stressed out today.

( )5. By the time I was five, I had started learning English.