Correct Answer: B

Rationale: Lignin is the correct answer because it is a type of fiber that is not a carbohydrate and provides structure to plant cell walls. Gums (choice A), pectin (choice C), and cellulose (choice D) are all types of dietary fiber that are carbohydrates. Gums are a type of soluble fiber, pectin is found in fruits and is a soluble fiber, and cellulose is a type of insoluble fiber found in plant cell walls.

Correct Answer: B

Rationale: Sugar alcohols are commonly found in low-calorie foods as sweetening agents without the calorie content of regular sugars. Choices A, C, and D are incorrect because sugar alcohols are not typically found in fermented foods, fruits, vegetables, or fiber supplements. Therefore, the correct answer is B.

Correct Answer: D

Rationale: The Dietary Reference Intake (DRI) for protein is primarily determined by an individual's body weight. This is because the body's protein requirement is proportionate to its size, which is generally reflected in the body weight. Therefore, choice D is correct. Choices A, B, and C are incorrect: While factors such as fatty acid intake, gender, and height can influence an individual's overall nutritional needs, they do not directly determine the DRI for protein.

Correct Answer: B

Rationale: People with phenylketonuria should avoid aspartame because it contains phenylalanine, which they cannot metabolize. Acesulfame-K, saccharin, and sucralose do not contain phenylalanine and are safe for individuals with phenylketonuria. Therefore, the correct answer is B. Acesulfame-K, saccharin, and sucralose are incorrect choices because they do not pose a risk for individuals with phenylketonuria due to the absence of phenylalanine in their composition.

Correct Answer: B

Rationale: The correct answer is B: Essential fatty acids are not manufactured by the body. These fatty acids must be obtained through the diet because the body cannot synthesize them. Choice A is incorrect because essential fatty acids can come from both animal and plant sources, not just from an animal source. Choice C is the correct characteristic of essential fatty acids. Choice D is incorrect because essential fatty acids are not produced by the body.