Provide your best answer for the following question. Give ONLY the answer, no other words or explanation.
For example:

Answer: <most likely answer, as short as possible; not a complete sentence, just the answer!>.

The question is: Pedro shook a can of soda. When the soda was opened, foam and soda burst from the can. Which statement best explains what happened?
The gas pressure was released from the can.
Foam and soda were released when the can was opened.