Which one of the following food materials contains all essential amino acids?

The correct answer is (d), soybean. Soybeans are a complete protein, meaning they contain all nine essential amino acids that the human body cannot produce on its own. They are also a good source of fiber, vitamins, and minerals.

Rice is a good source of carbohydrates and fiber, but it is not a complete protein. Milk is a good source of protein, calcium, and vitamin D, but it does not contain all nine essential amino acids. Eggs are a complete protein, but they are also high in cholesterol.

In conclusion, soybeans are the best choice for a food material that contains all essential amino acids.