Correct Answer: D

Rationale: The correct answer is 'D. triglyceride.' Triglycerides are composed of one glycerol molecule and three fatty acids, making them the primary form of stored fat in the body. Cholesterol (A) is a different type of lipid, phospholipids (B) have two fatty acids, and 'saturated' (C) refers to the structure of fatty acids, not a specific lipid containing 3 fatty acids.

Correct Answer: B

Rationale: Alcohol abuse is indeed a major cause of acute pancreatitis, along with gallstones, accounting for the majority of cases. While infections, diabetes, and obesity can also contribute to pancreatitis, they are not as prevalent as alcohol abuse and gallstones in causing acute pancreatitis.

Correct Answer: C

Rationale: The correct answer is C: hyperlipidemia. Antiretroviral drugs can often lead to elevated lipid levels (hyperlipidemia), which is a common side effect of this therapy. This increase in lipids can contribute to cardiovascular risk. Hypertension (choice A) is not typically associated with antiretroviral drug use. Hypothyroidism (choice B) and fluid retention (choice D) are also not commonly linked to antiretroviral therapy.

Correct Answer: B

Rationale: The correct answer is B: 'be obtained by the diet.' Essential nutrients are those that the body cannot synthesize in sufficient quantities and must therefore be obtained through the diet. Choice A is incorrect because not all essential nutrients need to be consumed daily; the frequency of consumption varies. Choice C is incorrect because not all essential nutrients are water-soluble; they can be water-soluble or fat-soluble. Choice D is incorrect because essential nutrients do not need to be consumed at every meal, but rather need to be included in the overall diet regularly.

Correct Answer: C

Rationale: Choice C is correct because iron absorption is indeed increased by Vitamin C and during pregnancy. The other choices are incorrect. Choice A is wrong as there are no universally accepted percentages for the iron needs of vegans and endurance athletes. Choice B is inaccurate as iron deficiency is actually one of the most common nutritional deficiencies worldwide. Choice D is incorrect because tannic acid and calcium in milk actually inhibit iron absorption rather than increasing it.