Which of the following drugs Is used In conjunction with diet therapy to reduce a patient's serum cholesterol level?

Azithromycin is an antibiotic used to treat various bacterial infections. It does not have any effects on cholesterol levels and is not indicated for the management of serum cholesterol. Its primary function is to combat infections rather than manage lipid profiles.

Lisinopril is an ACE inhibitor used primarily for managing hypertension and heart failure. While it can have beneficial effects on cardiovascular health, it does not directly affect cholesterol levels and is not prescribed for cholesterol reduction.

Sertraline is an antidepressant belonging to the selective serotonin reuptake inhibitor (SSRI) class. Its primary use is for treating depression and anxiety disorders, and it does not have any role in lowering cholesterol levels in patients.

Zolpidem is a sedative primarily used for the treatment of insomnia. It has no impact on cholesterol levels and is not used in any context related to cholesterol management or dietary therapy.