Edema in congestive heart failure occurs due to which mechanism, and which diuretic is commonly used to manage it?

• A. Reduced cardiac output leads to fluid overload and venous congestion; loop diuretics such as furosemide are commonly used.
• B. Increased cardiac output reduces venous return; hydrochlorothiazide is preferred.
• C. Decreased capillary permeability; spironolactone is first-line.
• D. Normal cardiac output with edema due to venous insufficiency; acetazolamide is used.

Answer: (A)