I'll give you a question, please answer with step-by-step reasoning process.
What do nephrons filter?\nOptions:\n- (A) Blood\n- (B) matter\n- (C) solutes\n- (D) Energy\n- (E) SO2\n- (F) Gases\n- (G) Energy.\n- (H) cations

(A)
Nephrons are the structural and functional units of the kidneys.

Blood is filtered in the kidney.

Nephrons filter blood.

.

So, the final answer is (A)