Answer the following question given this paragraph: 

Sublimation occurs when ice and snow change directly to water vapor. This also happens because of heat from the sun.


Q: When does sublimation occur?

 Choices:

- when the wind changes direction

- when the snow melts the ice caps

- when the ice and sand change directly into water vapors

- when the ice and snow change directly into water vapors

A:
when the ice and snow change directly into water vapors
