The caloric value of protein is:

Correct Answer: B

Rationale: Protein's caloric value is approximately 4-5.3 Kcal/g, with 5.3 being a standard estimate in some contexts, though 4 is more common; answer key indicates B.

Correct Answer: B

Rationale: Most iron absorption occurs in the duodenum/upper jejunum. Dietary iron is mostly ferric, ferritin stores thousands of atoms, ~70% of body iron is in hemoglobin, and absorption is ~10-15%.

Correct Answer: D

Rationale: Secretin inhibits gastrin secretion and stimulates HCO_3-rich pancreatic juice, not enzymes; it doesn't increase acid or emptying time.

Correct Answer: A

Rationale: The production of thyroid hormone is dependent on the intake of protein and iodine.

Correct Answer: B

Rationale: Cortisol is a mineralocorticoid produced by the adrenal glands. Cortisol acts to increase glucose levels in the blood. Cortisol also helps counteract the inflammatory response. The reduced production of cortisol hinders the older adult in dealing with stress.