Robert leaves a chocolate bar in his car while attending school all day. When he goes to his car in the afternoon, the bar has changed into a gooey liquid. Which statement BEST explains what happened to Robert's chocolate bar? A) The energy from the sun caused the chocolate to melt. B) The chocolate in the bar spread out due to entropy loss. C) The energy holding the solid bar together was lost over time and it became liquid. D) The liquid was the original state of the chocolate and over time it returned to this state.