Which of these is a common diuretic?

A common diuretic is a medication that promotes the excretion of water and salts from the body, primarily through increased urine production. Dyazide is a combination medication that includes two active ingredients: hydrochlorothiazide and triamterene. Hydrochlorothiazide is a thiazide diuretic, which helps to manage conditions such as hypertension and edema by facilitating the removal of excess fluid from the body.

In contrast, the other options represent medications used for different therapeutic purposes. Testim is a testosterone replacement therapy used to treat low testosterone levels, Estrace is an estrogen replacement therapy for menopausal symptoms, and Cozaar is an antihypertensive medication that falls under the category of angiotensin II receptor antagonists, used to control high blood pressure but does not function as a diuretic. Thus, the selection of Dyazide as a common diuretic is accurate due to its specific action in promoting diuresis.