The correct answer is D. Legumes : Nodules.
Beans, rice, and tea are all edible plants that are commonly used in food. Beans are a type of legume, which is a plant that produces pods containing seeds. Rice is a type of cereal, which is a grass that is cultivated for its edible seeds. Tea is a type of beverage that is made from the leaves of the Camellia sinensis plant.
Legumes are a type of plant that have a symbiotic relationship with bacteria called rhizobia. These bacteria live in nodules on the roots of legumes and fix nitrogen from the air, making it available to the plant. This is a beneficial relationship for both the legume and the bacteria, as the legume provides the bacteria with a place to live and the bacteria provides the legume with nitrogen.
Nodules are not a defining characteristic of legumes. Other plants, such as alder trees, also form nodules with nitrogen-fixing bacteria. Therefore, the pair of words “legumes : nodules” is the odd one out in the list.