HELP PLEASE FAST ASAP PLEASE HELP

D. Their ability to replicate very fast and natural mutations combine to allow them to evolve rapidly

Explanation:

They develop mutations in their DNA that can be resistant to the drugs given.

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.