The following nerve is a branch of lumbar plexus and emerges from anterior surface of psoas major muscle

Correct Answer: D

Rationale: Genitofemoral nerve emerges anteriorly from psoas major, unlike iliohypogastric/ilioinguinal (lateral), femoral (lateral/posterior), or lumbosacral trunk (medial). This specifies lumbar plexus anatomy, vital for surgical approaches, contrasting with other trajectories.

Correct Answer: C

Rationale: Urine acidification (H+ secretion) peaks in the collecting duct via intercalated cells not PCT, DCT, or ascending loop (diluting). This specifies pH regulation site, critical for acid-base, contrasting with earlier segments.

Correct Answer: D

Rationale: Renal lobule includes a medullary ray and adjacent cortex not pyramid alone, pyramid+cortex (lobe), or inter-pyramid cortex. This defines lobule anatomy, critical for histology, contrasting with lobe or cortex misdefinitions.

Correct Answer: A

Rationale: PCT reabsorbs ~80-90% of filtered bicarbonate not DCT, collecting duct, or ascending loop (no HCO3- transport). This specifies primary reabsorption site, critical for acid-base, contrasting with later segments.

Correct Answer: B

Rationale: Water moves by osmotic diffusion throughout nephron (solute-driven) not PCT-only or ADH-controlled obligatory (PCT inherent). This defines water handling, critical for urine formation, contrasting with restricted or hormonal errors.