Correct Answer: C

Rationale: The correct answer is vitamin E. Vitamin E is the major antioxidant found in cell membranes, where it plays a crucial role in protecting them from oxidative damage. Although B12, beta-carotene, and vitamin A are important nutrients with specific functions in the body, they are not the primary antioxidants found in cell membranes. Vitamin E specifically localizes in cell membranes to neutralize free radicals and prevent lipid peroxidation, making it an essential antioxidant for cellular health.

Correct Answer: A

Rationale: The first statement is correct as bacterial plaque can indeed metabolize sucrose, lactose, and fructose. However, the second statement is inaccurate. Fructose, despite being found naturally in honey and known also as levulose, is not less cariogenic than either sucrose or lactose. This means that its consumption does not result in fewer cavities or tooth decay. Therefore, the correct answer is that bacterial plaque can metabolize these sugars, but fructose is not less cariogenic. Choices B, C, and D are incorrect because they either wrongly assert that bacterial plaque cannot metabolize these sugars or wrongly claim that fructose is less cariogenic.

Correct Answer: D

Rationale: Short-chain fatty acids are the most water-soluble and are more easily absorbed into the bloodstream. Very long, long, and medium-chain fatty acids are less water-soluble and are absorbed at a slower rate compared to short-chain fatty acids. Therefore, the correct answer is D.

Correct Answer: A

Rationale: Individuals with lactose intolerance lack the enzyme lactase needed to break down lactose, the sugar in dairy products. Milk contains a high amount of lactose, making it crucial for those with lactose intolerance to limit their intake. Yogurt and cheese, on the other hand, have lower lactose content due to the fermentation process which reduces lactose levels, making them better tolerated by many with lactose intolerance. Corn syrup, although high in sugar, does not contain lactose and is unrelated to lactose intolerance. Therefore, the correct answer is 'milk' as it is a significant source of lactose, which can trigger symptoms in individuals with lactose intolerance.

Correct Answer: D

Rationale: The correct answer is choice D because medication for high cholesterol is typically not considered unless Therapeutic Lifestyle Changes (TLC), which include diet and exercise, have not proven effective after a three-month period. This approach ensures that lifestyle modifications are given a fair chance to lower cholesterol levels before resorting to medication. Choice A is incorrect because the number of risk factors for coronary heart disease does not dictate when to begin medication; it is about the effectiveness of lifestyle changes. Choice B is incorrect as the duration of coronary heart disease symptoms does not determine when to start medication; the focus is on the response to TLC. Choice C is incorrect because the coverage of prescription drugs by the patient's insurance does not influence the medical decision to use medication for high cholesterol; it is based on medical necessity and effectiveness of prior interventions.