Correct Answer: A

Rationale: The correct answer is A: Longitudinal and circular. Longitudinal and circular muscles are responsible for the movements that help propel food through the intestine. Choice B, expulsion and traction, is incorrect as these terms do not specifically relate to the types of muscular movement in the intestine. Choice C, tonus and clonus, refers to different types of muscle contractions and are not the primary movements in the intestine. Choice D, intermittent and continuous, does not accurately describe the specific types of muscular movement that occur in the intestine.

Correct Answer: C

Rationale: Low income is a significant factor contributing to marginal nutritional status due to limited access to nutritious food. While dependence on caffeine or acute illness can impact health, they are not as directly linked to marginal nutrition as low income. The size of the family unit may affect food distribution within the household but is not as directly related to marginal nutritional status as low income.

Correct Answer: B

Rationale: A normal weight-to-height ratio is a reliable indicator of good nutritional status as it suggests that the person is well-nourished and not underweight or overweight. Small muscle mass (choice A) can indicate malnutrition, a smooth tongue (choice C) can be a sign of vitamin deficiencies, and fragile skin (choice D) can be a sign of poor nutrition or other health issues, but they are not as direct indicators of good nutritional status as a normal weight-to-height ratio.

Correct Answer: C

Rationale: The recommended fat intake is between 20% to 35% of total daily calories. This range is considered optimal for maintaining a healthy diet. Choice A (10% to 15%) is too low and might not provide enough essential fats for the body. Choice B (10% to 35%) includes an upper limit that exceeds the generally accepted range. Choice D (40% to 55%) suggests a fat intake that is higher than what is recommended, which could lead to health issues if consumed regularly.

Correct Answer: C

Rationale: The primary function of carbohydrates as a food source is to supply energy. Carbohydrates are the body's main source of energy, providing fuel for various physiological functions. Choice A is incorrect because carbohydrates do not primarily regulate metabolic processes; that role is mainly attributed to enzymes and hormones. Choice B is incorrect because proteins are primarily responsible for building body tissue. Choice D is incorrect because fiber, not all carbohydrates, provides bulk in the diet.