On a hot summer day Lam walked home from his grandmothers with a chocolate bar in his pocket. When he arrived home the chocolate bar had melted in his pocket, which statement BEST explains why the chocolate bar melted?
A Heat transferred from the chocolate bar to his pocket.
B. Heat evaporated from his pocket to his chocolate bar.
c. Heat condensed from his leg to his chocolate bar in his pocket.
D. Heat transferred from the environment to the chocolate bar in his pocket.