Correct Answer: C

Rationale: Calcium is the most important nutrient for bone health and the prevention of osteoporosis. Calcium plays a crucial role in maintaining bone density and strength. Vitamin A is important for vision and immune function but is not directly related to bone health. Iron is essential for oxygen transport in the blood, while protein is important for muscle growth and repair. However, in the context of preventing osteoporosis, calcium is the key nutrient.

Correct Answer: B

Rationale: Phospholipids are a major component of cell membranes, providing structural integrity and facilitating cell signaling. Cholesterol (choice A) is also present in cell membranes but in smaller amounts and plays a different role. Saturated (choice C) and triglyceride (choice D) are not major constituents of cell membranes.

Correct Answer: D

Rationale: The correct answer is D. This information is crucial as it informs the mother of her options for expressing milk, which is the first step in being able to store and later feed it to her child while she's away at work. Choice A has been corrected to state that breast milk can be refrigerated for up to 4 days, providing a more accurate storage timeframe. Choice B has been revised to indicate that breast milk stored in a deep freezer can be kept for up to 12 months, aligning with the recommended storage duration. Choice C now highlights that heating breast milk in the microwave can degrade its nutritional quality, emphasizing the importance of using proper methods for warming breast milk and avoiding potential harm to the baby's health and well-being.

Correct Answer: A

Rationale: Pregnancy is the correct answer as it is most closely associated with a high rate of gastroesophageal reflux disease (GERD). During pregnancy, the growing fetus exerts pressure on the stomach, leading to the backflow of stomach acid into the esophagus, causing GERD. This physiological change is a common occurrence in pregnant individuals. Conversely, anorexia, hypertension, and diabetes mellitus are not typically linked to a high rate of GERD. While these conditions have their own effects on the body, they do not directly contribute to the mechanisms that cause GERD, unlike the physical changes associated with pregnancy. Therefore, choices B, C, and D are incorrect.

Correct Answer: B

Rationale: Pepsin, choice B, is the correct answer as it is a proteolytic enzyme that is essential for the breakdown of large protein molecules in the stomach. Gastric lipase, choice A, is incorrect because it primarily targets fats, not proteins, hence it is not involved in protein hydrolysis. Mucus, choice C, is incorrect as it serves to protect the stomach lining from acidic gastric juices and does not play a direct role in protein digestion. Intrinsic factor, choice D, is incorrect as it is vital for the absorption of Vitamin B12 in the small intestine and doesn't participate in the process of hydrolyzing proteins.