The toxin of Vibrio cholerae causes profuse diarrhea because it
A) modifies a G protein involved in regulating salt and water secretion.
B) decreases the cytosolic concentration of calcium ions, making the cells hypotonic to the intestinal cells.
C) binds with adenylyl cyclase and triggers the formation of cAMP.
D) signals inositol trisphosphate to become a second messenger for the release of calcium.
E) modifies calmodulin and activates a cascade of protein kinases.
Answer: A