Which of the following sentences uses parallel structure?

Question

It is important to study, staying on top of your homework, and go to class.
My three favorite activities are singing, dancing, and to go to the mall.
There is nothing he likes better than to cook, eating, and cleaning up.
When you meet someone, you should say hello, smile, and shake hands.

Answer 1

When you meet someone, you should say hello, smile, and shake hands.