Why did the combination of corn and beans prove so crucial to the diet of early americans? a. beans neutralized an otherwise toxic compound in archaic forms of corn. b. corn and beans grew under different conditions and in different places, making harvests more reliable. c. corn remedied the digestive issues that beans created. d. the beans added amino acid to the corn, making the combination as nutritious as meat?

d. the beans added amino acid to the corn, making the combination as nutritious as meat?

Explanation:

Beans is a major source of proteins, fiber, fat and some essential nutrients as well as vitamins. Protein generally is a polymer of different amino acids.

The major nutrient in corn is carbohydrate (in form of starch), fiber, fat, a small amount of protein and some important nutrient elements.

Meat is rich in protein, fat, essential nutrient elements, vitamins as well as essential and non-essential amino acids.

Hence, in order for corn to be as nutritious as meat, the complimentary action of beans is needed.

The correct option is d.

1. efficient use of space

2. elimination of groundwater contamination

3. energy generation

4. lower carbon footprint