Activation energy of forward and backward process of reaction are 60 kJ and 40 kJ `"mol"^(-1)` respectively . Which of the following are true the reaction ?
A. It is endothermic reaction
B. It is exothermic reaction
C. Heat of reaction is +20kJ `"mol"^(-1)`
D. Thershol enregy of reaction is 100 kJ `"mol"^(-1)`