Question

question 19 of 20 : select the best answer for the question. 19. a/an ______ is a substance that can be broken down and used as sustenance that’s essential for life. a. calorie b. enzyme c. nutrient d. carb mark for review (will be highlighted on the review page) << previous question next question

Explanation:

• Option A: A calorie is a unit of energy, not a substance, so A is incorrect.
• Option B: An enzyme is a biological catalyst, not a substance used as sustenance, so B is incorrect.
• Option C: A nutrient is a substance that can be broken down and used as sustenance essential for life, which matches the definition.
• Option D: A carb (carbohydrate) is a type of nutrient, but the definition in the question is more general and applies to nutrients as a whole, so D is too specific.

Answer:

C. nutrient