Nutrient-dense foods are better than foods that are less nutritious because a. nutrient-dense foods give the body protein, vitamins, minerals, and water. b. nutrient-dense foods taste better than less nutritious foods. c. less nutritious foods cost more than nutrient-dense foods. d. nutrient-dense foods have fewer calories than less nutritious foods.

If I just give you the answer they will delete it so I have to explain it
The question asks Nutrient Dense foods are better than foods that are less Nutritious 
Let's define a Nutrient Dense food,  it is a food that is dense in Nutrients.
The question states "less nutritious food".  
For example
An Egg is more nutrient dense that a Cheeze Doodle

So Now which answers makes sense to you?

A. nutrient dense foods give the body protein, vitamins, minerals, and water.
Does an Egg do that?  Does a Cheeze Doodle do that?
Eggs give nutients other than calories. a Cheese doodle does not
B, Nutrient Dense foods taste better
Which tastes better to you and Egg or Cheese Doodle?  
For this it depends on the individual and the food.
Some people don't like the taste of liver, but it is one of the most nutritious foods you can eat.
C.  Less nutritious foods cost more than Nutrient dense foods
Which is more expensive 1 serving of Egg or 1 serving of Cheese Doodle?
this depends on the person and the food choice

D.Nutrient Dense foods have fewer calories than less nutritious foods
Again The answer here depends on the food choice

Instead of calling something a less nutritious food, I would have called them empty calories.  Meaning that they give calories with low amount of nutrition.
So have you figured out which is the best answer?  
The best answer is A. Nutrient Dense foods give the body