He doesn't have any vomiting or abdominal pain

A 23-year-old man presents to the emergency room complaining of massive watery diarrhea for 6 hours. He doesn’t have any vomiting or abdominal pain. Stool culture reveals a curved; gram negative rod which secretes an enterotoxin contains subunit A and a binding subunit B.
What is the most likely reason for this patient’s massive diarrhea?
A- Deficiency in the brush border enzymes
B- Decreased production of cAMP
C- Increased production of cAMP
D- Destruction of the absorptive epithelium
E- Increased motility of the small intestine

Ans D