B. some species die out when environmental changes occur
Answer:
Flavin Adenine Dinucleotide
Explanation:
"Flavin adenine dinucleotide (FAD) is synthesized from riboflavin and two molecules of ATP. Riboflavin is phosphorylated by ATP to give riboflavin 5′-phosphate (also called flavin mononucleotide, FMN). FAD is then formed from FMN by the transfer of an AMP moiety from a second molecule of ATP."
I think its B but I'm not sure .. sorry