Many plants have evolved mutualistic relationships with nitrogen-fixing bacteria because: select one: a. the bacteria utilize nitrogen to produce energy for the plants; the plants provide the source of the nitrogen for the bacteria b. the bacteria transform nitrogen into useful forms for the plants; the plants provide carbohydrates c. the bacteria protect the plant from harmful effects of nitrogen compounds such as ammonia; the plants provide carbohydrates for the bacteria d. there is not a mutualistic relationship between nitrogen-fixing bacteria and plants e. the bacteria provide natural immunities to the plants; the plants shelter the bacteria from predators