(E) Is Reaction 3, taken as a whole from Point A to Point C, endothermic or exothermic?...

(E) Is Reaction 3, taken as a whole from Point A to Point C, endothermic or exothermic? What about Reaction 4? [Label both Figure 4.12 and Figure 4.13 with one of these two terms.]

(Reference Figure 4.12 and 4.13)