The hormone that regulates water reabsorption by the kidneys

Correct Answer: D

Rationale: Vasopressin increases water permeability specifically in the collecting ducts, not throughout all tubules.

Correct Answer: D

Rationale: RAS is activated by low blood pressure in nephron arterioles and reduced distal tubule flow, detected by the macula densa.

Correct Answer: D

Rationale: ANP increases glomerular filtration rate and inhibits renin to reduce blood volume and pressure.

Correct Answer: D

Rationale: ANP inhibits, rather than increases, aldosterone secretion to promote sodium loss.

Correct Answer: D

Rationale: Low plasma pH (acidosis) causes CNS depression and confusion due to altered neural function.