What Happens to Snowflakes as They Become Progressively Buried Within

Multiple Choice

What happens to snowflakes as they become progressively buried within glaciers?

A) They become less dense because of large amounts of trapped air.
B) They begin to melt as they are insulated from the cold air.
C) They become interlocking crystals of ice.
D) They can become brighter white because of trapped air.
E) All of these.