Correct Answer: C

Rationale: Vitamin C plays a crucial role in protecting the integrity of cellular membranes. It is essential for collagen synthesis, which is important for wound healing and maintaining skin, blood vessels, and other tissues. Choice A is incorrect as the transcription of DNA to RNA is facilitated by vitamin A. Choice B is incorrect as calcium absorption and regulation are functions of vitamin D. Choice D is incorrect as vitamin K serves as a catalyst for the synthesis of blood-clotting factors, not vitamin C.

Correct Answer: A

Rationale: The correct answer is A, Beans. Beans are known to be a good source of protein compared to the other options provided. While red peppers, asparagus, and celery are nutritious vegetables, they do not contain as much protein as beans do. Red peppers are high in vitamin C, asparagus is rich in vitamins and minerals, and celery is low in calories and a good source of fiber, but they are not significant sources of protein.

Correct Answer: A

Rationale: Both the statement and the reason are correct and related. Inadequate intake of vitamin A in lower socioeconomic groups is due to a lack of resources to purchase and consume vegetables and fruits. This is supported by the fact that the average intake in the United States meets the Recommended Dietary Allowance (RDA) for vitamin A intake, except in lower socioeconomic groups. These individuals often lack the financial means to buy, prepare, and eat a variety of fruits and vegetables, leading to deficiencies. It's important to note that because vitamin A can be stored in the liver, most adults have sufficient quantities to maintain health. Choices B, C, and D are incorrect because the statement and reason are both accurate and logically connected, as the lack of resources directly impacts the ability to obtain necessary sources of vitamin A.

Correct Answer: C

Rationale: The correct answer is C. Maintenance of more than 200 genes is not a function of vitamin A; instead, it is a function of Vitamin D. Vitamin A plays a crucial role in the prevention of night blindness by aiding in the production of the visual pigment rhodopsin. It also supports the growth of soft tissues and bone, as well as the integrity of body openings and their linings. Choice C is incorrect because the maintenance of genes is primarily associated with Vitamin D, not Vitamin A.

Correct Answer: A

Rationale: Both statements are true. The effect of vitamin A on the growth of soft tissues and bones naturally extends to the teeth and surrounding structures. Enamel hypoplasia, involving defective enamel matrix and incomplete calcification of enamel and dentin, can be due to vitamin A deficiency. The effect of this vitamin upon surrounding bone directly affects spacing patterns of the teeth within the bone and dentition. Choice A is correct because both statements accurately describe the influence of vitamin A on tooth development. Choices B, C, and D are incorrect as they do not reflect the accuracy of the statements provided.