Autotroph is to producer as heterotroph is

consumer

Explanation:

Autotroph is to producer as Heterotroph is to consumer. Autotrophs make their own food, which makes them producers. While Heterotrophs cannot make their own food, and must obtain it from another source, making them consumers.

Consumer that eats a producer or another consumer

image result for how many calories of energy will 20 grams of carbohydrates provide in one gram provides 4 calories

consuming the right balance of protein, carbohydrates and fat can you maintain a healthy weight and optimize your energy levels. protein and carbohydrates both contain 4 calories per gram, while fat provides 9 calories per gram.

it is either c or d and i know for sure it is not a or b