Kidney produces urine by:

Correct Answer: D

Rationale: Urine production involves ultrafiltration (glomerulus), reabsorption (tubules), and secretion (tubules) all apply. Ultrafiltration forms filtrate, reabsorption recovers water/nutrients, and secretion adds waste, collectively shaping urine. Excluding any step (secretion, ultrafiltration, or reabsorption) ignores a key process, making 'all' the accurate choice. This encompasses renal function, vital for waste excretion, contrasting with single-process views.

Correct Answer: D

Rationale: Horseshoe kidney is trapped by the inferior mesenteric artery not ureter length, pole fusion (cause), SMA, or aorta; IMA blocks ascent. This specifies obstruction, critical for anomaly, contrasting with causal or higher structures.

Correct Answer: D

Rationale: Prostatic urethra forms from vesicourethral canal (upper), mesonephric ducts (mid), and pelvic sinus (lower) all contribute. 'All' fits mixed origin, critical for male anatomy, contrasting with partial sources.

Correct Answer: B

Rationale: Kidneys activate vitamin D convert 25-hydroxy-D to calcitriol (e.g., calcium regulation). Vitamin A is liver-processed not kidney. Vitamin E is antioxidant not activated. Vitamin K is clotting-related liver role. Vitamin D's renal activation distinguishes it, critical for bone/mineral homeostasis, unlike other vitamins.

Correct Answer: A

Rationale: Micturition is urination bladder emptying (e.g., reflex/voluntary). Mastication is chewing oral. Deglutition is swallowing digestive. Defecation is fecal rectal. Micturition's specificity distinguishes it, critical for urinary terminology, unlike digestive or fecal processes.