New forms of drug-resistant bacteria can evolve quickly because A
when a drug kills most of the bacteria, the ones left to breed are those that have a natural resistance to the drug.

B
when scientists genetically engineer bacteria they use natural selection.

C
scientists use extinction to selectively breed bacteria.

D
a drug causes mutations in the bacteria, leaving only mutated bacteria left to breed.

A

Explanation:

the answer is c. it will give up it's valence electron to the other atom.

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.