What kind of antibiotics are responsible for a 58-year-old alcoholic man with multiple dental caries develops a pulmonary abscess and is treated with antibiotics? Several days later, he develops nausea, vomiting, abdominal pain, and voluminous green diarrhea.

I think it should be Clindamycin. Any time you see the development of diarrhea in the same question stem as the words treated with antibiotics, you should immediately think of pseudomembranous colitis. pseudomembranous colitis is caused by clostridium difficile and typically occurs as a result of treatment with clindamycin or ampicillin.