I will give 60 points!
What happens to Cinder in the medical lab?

She found out when she woke up that she was 36.28 percent not human

Explanation:

The bacteria that lives on the roots of plants is called nitrogen fixing bacteria.
This type of bacteria turns nitrogen gas into nitrogen compounds that plants can use - this can also occur by the action of lightening as the energy from lightning makes nitrogen react with oxygen in the air to give nitrates.

So the answer would be C, I think.