Here's a problem to solve: A student blew air into a beach ball and sealed it. She then pushed on the middle of the beach ball. What happened to the air inside the beach ball?

Among the 4 following options, which is the correct answer?

- A: The air in the beach ball escaped.
 
- B: The air in the beach ball became a liquid.
 
- C: The type of air in the beach ball changed.
 
- D: The shape of the air in the beach ball changed.
 