What is the number of known crystalline phases of water ________?

135

A. 4
B. 8
C. 17
D. 15

Explanation:

Ice is the name given to any one of the 15 known crystalline solid phases of water. In non-scientific contexts, it usually describes ice Ih, which is the most abundant of these phases. It can appear transparent or an opaque bluish-white color depending on the presence of impurities such as air.