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.

Correct Answer: C

Rationale: Damage to the stomach can lead to a reduced ability to produce gastric acid (Choice C) and intrinsic factor, the latter of which is crucial for vitamin B12 absorption (Choice D). That's why these two choices are correct. The stomach doesn't play a direct role in the digestion of carbohydrates (Choice A) as this process primarily occurs in the small intestine with the help of pancreatic enzymes. Similarly, bile is produced by the liver and stored in the gallbladder, not the stomach, hence stomach damage wouldn't lead to an inability to produce or secrete bile (Choice B).

Correct Answer: C

Rationale: The correct answer is C: Carcinomas. Carcinomas are cancers that originate from epithelial tissues, which are the tissues lining the surfaces of organs and structures in the body. Leukemias (choice A) are cancers of the blood-forming cells, not epithelial tissues. Myelomas (choice B) are cancers that develop in plasma cells in the bone marrow, not epithelial tissues. Sarcomas (choice D) are cancers that arise from connective tissues like bone, cartilage, or muscle, not epithelial tissues. Therefore, choices A, B, and D are incorrect in the context of cancers originating from epithelial tissues.

Correct Answer: C

Rationale: The Recommended Dietary Allowance (RDA) is the correct answer for James because it provides the daily intake level that meets the nutrient needs of most healthy individuals in a specific age and gender group. Choice A, EAR (Estimated Average Requirement), represents the average daily nutrient intake level estimated to meet the requirement of half the healthy individuals in a particular life stage and gender group. Choice B, UL (Tolerable Upper Intake Level), is the maximum daily intake unlikely to cause adverse health effects. Choice D, DV (Daily Value), is a general guide used for food labeling that represents how much a nutrient in a serving of food contributes to a daily diet based on a 2000-calorie daily intake.

Correct Answer: A

Rationale: If MEGA was only detected in feces and not in urine, it was not absorbed into the bloodstream. Absorbed compounds typically appear in urine after processing by the body. The correct answer is A because the presence of a compound in feces indicates that it was not absorbed by the body and passed through the digestive system. Choices B, C, and D are incorrect as they do not align with the process of absorption and excretion in the body.