The Questions Below Refer to the Following Diagram

Multiple Choice

The questions below refer to the following diagram:
-Why is this reaction considered to be exothermic?

A) Because energy difference B is greater than energy difference C.
B) Because energy difference B is greater than energy difference A.
C) Because energy difference A is greater than energy difference C.
D) Because energy difference B is greater than energy difference C plus energy difference A.
E) Because energy difference A and energy difference C are about equal.