You have a series of four chemical reactions (1->2->3->4). How do you calculate the triangleH2 if you know the other triangleH values?

A. Triangle H2= triangleH1 + triangleH3 -triangleH4

B. Triangle H2= triangleH1 + triangleH3 + triangleH4

C. Triangle H2= triangleH4 - (triangleH1 + triangleH3)

D. Triangle H2= (triangleH1)(triangleH3)(triangleH4)