The correct answer is (a). Wheat grains are seeds.
A seed is a small, embryonic plant enclosed in a protective coat. It is the product of the ripened ovary of a flowering plant, and it contains an embryo, a food supply, and a protective coat. The embryo is the beginning of a new plant, and the food supply will nourish it until it can grow on its own. The protective coat protects the embryo from damage and helps to keep it moist.
Wheat grains are the seeds of the wheat plant. They are small, oval-shaped grains that are typically about 1/2 inch long. Wheat grains are a major source of food for humans, and they are also used to make flour, bread, pasta, and other baked goods.
Option (b), fruits, is incorrect because fruits are the reproductive organs of flowering plants. They are typically sweet and fleshy, and they contain seeds. Wheat grains, on the other hand, are not sweet or fleshy, and they do not contain seeds.
Option (c), modified fruits, is incorrect because wheat grains are not modified fruits. They are simply the seeds of the wheat plant.
Option (d), entire seeds, is incorrect because wheat grains are not entire seeds. They are the embryos of wheat plants, and they are enclosed in a protective coat.