Butter Is Solid at Room Temperature Yet Liquid at Higher

Butter is solid at room temperature yet liquid at higher temperatures because

A) heat causes formation of double bonds in the fatty acid molecules.
B) butter is more saturated at room temperature.
C) van der Waals forces holding the fat molecules together are broken.
D) addition of the milk protein helps the fat molecules aggregate at room temperature.
E) loss of chaperone molecules allows for the separation of the monomers.