Final answer:
Correct option (A) Vegans must carefully combine plant proteins to obtain all essential amino acids, as most plant sources do not provide a complete protein profile on their own.
Step-by-step explanation:
Vegans need to pay special attention to the protein they eat because plant proteins often lack one or more essential amino acids, making it more challenging to obtain a complete protein profile from single plant sources. Unlike animal proteins, which typically contain all essential amino acids, most plant sources have one or more limitations in their amino acid composition.
However, by consuming a variety of plant foods and pairing those with complementary proteins, vegans can ensure they get all the essential amino acids their bodies require. For example, eating beans with rice or combining lentils with bread made from wheat can create a complete protein source. Soybeans are a notable exception as they contain all essential amino acids, making them a valuable protein source for vegans. Consuming a variety of vegan protein sources such as legumes, nuts, and seeds is essential for a balanced vegan diet.