A 40-year-old patient presents with frequent episodes of heartburn, regurgitation, and a sour taste in the mouth after meals. Symptoms are worse when lying down or bending over. Which of the following conditions is the most likely cause of these symptoms?

Correct Answer: B

Rationale: Hiatal hernia allows acid reflux into the esophagus, worsened by lying down or bending, causing heartburn and regurgitation.

Correct Answer: C

Rationale: A large surface area, due to villi and microvilli, enhances nutrient absorption efficiency.

Correct Answer: B

Rationale: Peptide hormones bind to membrane receptors, triggering secondary messengers inside the cell.

Correct Answer: B

Rationale: Glomerular capillaries are in Bowman's capsule, where filtration occurs.

Correct Answer: D

Rationale: The countercurrent multiplier in the loop of Henle concentrates urine by moving sodium ions.