Answer : C Pseudomembranous colitis
Pseudomembranous colitis is a generic term for an inflammatory disease of the colon that is characterized by exudative plaques on the mucosa.
Antibiotic therapy eliminates the normal mixed flora of the colon and facilitates the overgrowth of Clostridium difficile, leading to an acute infection of the colon.
The exotoxins produced by C. difficile cause intestinal necrosis, with superficial ulcers covered by a thick fibrinopurulent exudate.
The other choices are not related to antibiotic therapy and are not associated with the development of these exudative plaques.