The toxin of Vibrio cholerae causes profuse diarrhea because it
A. modifies a G protein involved in regulating salt and water secretion.
B. modifies calmodulin and activates a cascade of protein kinases.
C. signals IP3 to act as a second messenger for the release of calcium.
D. binds with adenylyl cyclase and triggers the formation of cAMP.
E. decreases the cytosolic concentration of calcium ions, making the cells hypotonic.
Answer: A