Explanation:

- Sunflower: Not typically the highest in protein. Used more for its oil content than protein.

- Soybean:

- ?? Highest in protein content among plant sources.

- Used widely in tofu, soy milk, and meat substitutes.

- Provides all essential amino acids.

- Correct Answer

- Grams (Chickpeas):

- Moderate protein source.

- Popular in vegetarian diets.

- Wheat:

- Contains some protein but mainly a carbohydrate source.

- Used mostly for energy rather than protein.