Correct Response: D. Water expands its volume as it freezes. This property causes water that has moved into rock fractures and crevices to push against the rock when temperatures drop below freezing. The pressure created by the expansion of water is an important cause of mechanical weathering in regions where temperatures drop below freezing. The slight change in water's density and volume as it warms above freezing (A) is not a major factor in mechanical weathering. Water's high specific heat (B) and relatively high surface tension (C) are not primarily responsible for water's ability to mechanically weather rock.