Much Research Is Being Done to Increase the Nitrogen-Fixing Ability

Much research is being done to increase the nitrogen-fixing ability of plants with root nodules. Why is this an important goal for agricultural researchers?

A) Decreasing the size of nodules will allow plants to fix more nitrogen into their own molecules.
B) Nitrogen is an essential component of the amino acids used to form protein.
C) Increasing the nitrogen-fixing ability of plants will allow them to make better use of nitrogen fertilizers.
D) Removing the bacteria from the root nodules will allow more fixed nitrogen to be available to the plants.