Explanation:

The correct option is (C) Soyabean. Soyabean is a leguminous crop that forms a symbiotic relationship with nitrogen-fixing bacteria (Rhizobium) in its root nodules. These bacteria convert atmospheric nitrogen into usable forms, thereby enriching the soil with nitrogen and reducing or eliminating the need for external nitrogen fertilizers. Options (A) Oat, (B) Rice, and (D) Maize are all cereal crops that are heavy feeders of nitrogen and typically require significant nitrogen fertilization for optimal growth and yield, as they lack this symbiotic nitrogen-fixing capability.