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.

Atp is is our little "pocket" of energy. of course, if you have too little, then it means you have too little energy, and you'll pass out. the way to not have enough, is to have no energy sources (glucose, fats, proteins). you can't have too many atp molecules. cycles like the krebs cycle produce it, but if you have too much of any substrate (or too little for that matter), the cycle stops and atp is no longer made (it stops until substrate levels are such that the process can go on). in any case, this is unlikely since atp is constantly hydrolyzed and remade, even while you're asleep. you won't have too much. if you have zero, you are dead or dying.