Why Do Birds Secrete Uric Acid as Their Nitrogenous Waste

Why do birds secrete uric acid as their nitrogenous waste? Because uric acid

A) is readily soluble in water, permitting its release in dilute urine.
B) is produced from their low- protein diet.
C) is metabolically intermediate to synthesize than other excretory products, balancing metabolic costs and water loss.
D) requires little water for nitrogenous waste disposal, thus conserving water and reducing body mass.