The answer is a because you're not focusing on numbers (quantities), you're simply observing something
I am not sure what the answer(s) for, "which is not a major function of the kidney?" is but I can guess that your answer for that question might be, regulation of blood cell size. Also, the normal ph range of urine in humans is 6! I hope this helps!
Cell- <span>the smallest structural and functional unit of an organism, typically microscopic and consisting of cytoplasm and a nucleus enclosed in a membrane. Microscopic organisms typically consist of a single cell, which is either eukaryotic or prokaryotic.</span>