Final answer:
Combining beans with rice is true in forming a complementary protein, which means they collectively provide the full spectrum of essential amino acids necessary for a nutritionally complete protein source. option a is correct.
Step-by-step explanation:
It is true that combining beans and rice creates a complementary protein. Most plant foods do not contain all the essential amino acids needed by the human body, which are known as complete proteins. However, different plant foods can be combined to provide all the essential amino acids. Beans are typically low in the amino acid methionine but high in lysine, while rice is low in lysine but high in methionine.
When eaten together, such as in the popular dish of beans and rice, they complement each other to form a complete protein profile. This concept also applies to other plant-based food pairings such as refried beans and tortillas, pea soup and rye bread, beans and pasta, baked beans and brown bread, and peanut butter on whole wheat bread.
Adding animal proteins to a meal can also help supply missing amino acids, enhancing the nutritional value of the meal. For example, combining pasta with cheese or adding small pieces of chicken to a vegetable stir-fry boosts the total amino acid content.