The Mechanism for Excreting Nitrogenous Waste in Aquatic Animals Was

The mechanism for excreting nitrogenous waste in aquatic animals was ineffective on land because

A) land animals concurrently developed a more efficient reproduction system.
B) land animals found better food sources.
C) land animals had a more difficult time with water balance than aquatic species since water was not always available on land.
D) aquatic animals did not have as much protein in their diets as did land animals.