Critical Reasoning (CR) | Re: Rhizobium bacteria living in the roots of bean plants or oth

Confused between B and E.
I marked B for the following reasons-

If we negate Option B - artificial fertilizer is used for not only nitrogen supply but also some nutrient X. Assume before the special stain was developed- you used 100 kg of Artificial fertilizer for your land, and now even after special stain is developed you need to use same 100 kg of artificial fertilizer to supply nutrient X. RIGHT?

And if we negate option E- Rhizobium bacteria living in the roots of wheat would not produce