Correct Answer: A

Rationale: The correct answer is A: Obesity. Among older adults, obesity is the most common nutritional disorder. This is often attributed to reduced physical activity levels and changes in metabolism that occur with aging. Choice B (Underweight) is less common among older adults as compared to obesity. While choices C (Vitamin deficiency) and D (Dehydration) are important nutritional issues, they are generally not as prevalent as obesity in the older adult population.

Correct Answer: A

Rationale: The statement is accurate. Scurvy is indeed caused by a deficiency in ascorbic acid, which is another name for Vitamin C. This vitamin plays a crucial role in the synthesis of collagen, a protein that helps in the formation and strength of skin, blood vessels, tissues, and bones. When the body lacks Vitamin C, it cannot produce enough collagen, leading to symptoms associated with scurvy such as bleeding gums and weakened immunity. The choice 'False' is incorrect because it contradicts the proven medical and scientific understanding of the causes of scurvy. Choices 'C' and 'D' are marked as 'Not applicable' because the question only requires a true or false answer.

Correct Answer: A

Rationale: Statistical data suggest that Caucasians generally have lower rates of type 2 diabetes compared to the other ethnic groups listed in the choices. This is not to say that Caucasians are immune to the disease, but rather that they have fewer reported instances. On the other hand, African Americans and Pacific Islanders are often identified as groups with a significantly higher risk and prevalence of type 2 diabetes. Asian Indians also exhibit higher rates compared to Caucasians. It is important to note that these are general trends observed in statistical data, and individual health outcomes can vary based on various factors such as lifestyle, diet, and genetics, among others. Therefore, the correct answer is A: Caucasians because they generally have the lowest rates of type 2 diabetes when compared to the other ethnic groups mentioned.

Correct Answer: B

Rationale: Cariogenic foods and beverages lower the pH level in the mouth to below 5.5. This is a critical threshold, as it is the point at which enamel begins to demineralize, increasing the risk of dental caries. Therefore, options 'A', 'C', and 'D' are incorrect. Although a pH level of 5, as suggested by option 'A', would indeed lead to demineralization, it's not the threshold value. The pH levels suggested by options 'C' and 'D' (6 and 6.5, respectively) are higher than the critical value of 5.5, which means they would not initiate enamel demineralization and the subsequent risk of dental caries.

Correct Answer: A

Rationale: The term for the act of performing beneficial services rather than harmful ones is 'Beneficence'. Beneficence refers to actions that enhance the well-being of others. In the healthcare context, beneficence ensures that health services are advantageous and beneficial to patients. 'Disclosure' (choice B) is the act of revealing information, not directly related to whether actions are beneficial or harmful. 'Maleficence' (choice C) is the opposite of beneficence, involving actions that can cause damage or harm. 'Justice' (choice D) denotes fairness and equality, important in various contexts but not specifically related to performing beneficial services.