I believe it is A because the plant is offering protection while the bacteria is converting it in to nitrogen that the plant can use!
So what is the question about
i don't understand
Answer: You should learn the symbols for the eight most abundant elements in the Earth's crust (Oxygen (O), Silicon (Si), Aluminum (Al), Calcium (Ca), Iron (Fe), Magnesium (Mg), Sodium (Na), and Potassium (K) .
Explanation:
