In the fluid catalytic cracker (FCC), the cracking reaction is _____________ (i) and the regeneration is _______________ (ii) _______________?
A. (i) exothermic (ii) endothermic
B. (i) exothermic (ii) exothermic
C. (i) endothermic (ii) endothermic
D. (i) endothermic (ii) exothermic