Developing Bird Embryos Excrete Most of Their Nitrogenous Waste as Uric

Multiple Choice

Developing bird embryos excrete most of their nitrogenous waste as uric acid because ________.

A) it is less metabolically expensive to produce compared to other waste products
B) it has a low solubility in water and is less toxic to the embryo than other forms of waste
C) it requires less energy to transport across the egg shell
D) it can be recycled by the embryo to make new protein