Here's a problem to solve: As an airplane climbs in the sky, the pilot notices ice crystals forming on the windshield. This happens because

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

- A: blizzards occur more often at higher altitudes.
 
- B: friction with the atmosphere causes ice to develop.
 
- C: water evaporates faster at higher altitudes, resulting in ice crystals.
 
- D: moisture on the outside of the plane freezes due to colder air at higher altitudes.
 