The cholera toxin, an AB exotoxin, attaches an ADP-ribose group to the host's stimulatory G factor (Gs). The normal function of Gs is to stimulate the host's adenylate cyclase, which produces the second messenger molecule cAMP. This toxin-mediated ADP-ribosylation of Gs has which of the following effects?a. inactivation of Gs, causing a decrease in cAMP levels and resulting in decreased ion transport from the infected host cell. b. constant activation of Gs, causing an increase in cAMP levels and resulting in decreased ion transport from the infected host cell. c. inactivation of Gs, causing a decrease in cAMP levels and resulting in increased ion transport from the infected host cell. d. constant activation of Gs, causing an increase in cAMP levels and resulting in increased ion transport from the infected host cell.