Given these reactions: A r 2B ∆H = 40

. Given these reactions: A r 2B ∆H = 40 kJ B r C ∆H = -50 kJ 2C r D ∆H = -20 kJ Calculate ∆H for the reaction; D + A r 4C. 

(A) –100 kJ 

(B) –60 kJ

 (C) –40 kJ 

(D) 100 kJ