Which of the following is an antibiotic?

The correct answer is Cleocin, which is the brand name for clindamycin, an antibiotic used to treat various bacterial infections. It works by inhibiting bacterial protein synthesis, effectively slowing or halting the growth of bacteria. This medication is commonly prescribed for skin infections, respiratory tract infections, and infections of the bones and joints, among others.

Amiodarone is an antiarrhythmic medication used to treat and prevent certain types of serious irregular heartbeats. Pamelor, known generically as nortriptyline, is a tricyclic antidepressant used primarily for treating depressive disorders and sometimes for chronic pain management. Evista, or raloxifene, is a medication used primarily for the prevention and treatment of osteoporosis in postmenopausal women, as well as for certain types of breast cancer. These alternatives all serve different therapeutic purposes, which is why Cleocin stands out as the only antibiotic among the options provided.