Correct Answer: B

Rationale: The correct answer is B: BMI > 31. A BMI over 31 is considered a high-risk factor for coronary heart disease as it indicates obesity, which is strongly linked to cardiovascular issues. Triglycerides > 150 mg/dL (choice A) can contribute to heart disease risk but are not as specific as BMI in assessing overall risk. LDL cholesterol < 128 mg/dL (choice C) is actually a desirable level, indicating lower risk. A blood pressure of 128/82 mmHg (choice D) is within normal range and not a high-risk measure specifically for coronary heart disease.

Correct Answer: A

Rationale: Folate is crucial before conception to prevent neural tube defects. Neural tube development occurs early in pregnancy, often before a woman knows she is pregnant.

Correct Answer: C

Rationale: The correct answer is C, leptin. Leptin is a hormone produced by fat cells that helps regulate energy balance by suppressing hunger, thus aiding in the regulation of body fat. Glucagon (choice A) is a hormone that raises blood glucose levels, ghrelin (choice B) stimulates appetite, and insulin (choice D) regulates blood sugar levels and promotes glucose uptake.

Correct Answer: B

Rationale: The correct answer is B: eyes, nerves, and kidneys. In diabetes, major complications result from damage to small blood vessels that supply these organs. Damage to the eyes can lead to retinopathy, to the nerves causing neuropathy, and to the kidneys causing nephropathy. Choices A, C, and D are incorrect as they do not represent the typical major complications associated with diabetes.

Correct Answer: C

Rationale: The correct answer is C: providing rigidity for the bones. Almost all of the calcium in the body is utilized for maintaining the strength and structure of bones and teeth. Calcium plays a crucial role in skeletal health by providing rigidity and support to the skeletal system. Choices A, B, and D are incorrect because while calcium is essential for various physiological functions like nerve transmission, cell energy production, and muscle contraction, the majority of calcium in the body is primarily allocated for bone health.