Question

Living organisms require nitrogen to make nitrates and nitrites, which are used to build _______________________.

Answer 1

Proteins! Because proteins have the structure nh2 -cooh - ch <- since it requires nitrogen, this is the answer!
it cant be a) or d) which is the same thing because it only contains carbon, hydrogen and oxygen and doesn't need nitrogen. c) starch also only have c, h and o
I hope I helped! :)