Which is a recognized source of variation for evolution

1.The rise of methicillin-resistant Staphylococcus aureus (MRSA) can be considered to be an example of artificial selection because
A. S. aureus is cultivated by humans to replenish the soil with nutrients.
B. humans synthesize methicillin and create environments in which bacteria frequently come into contact with methicillin.
C. Humans are becoming resistant to bacteria by taking methicillin.
D. humans purposefully raise MRSA in large fermenters in an attempt to make the bacteria ever-more resistant.

2.Although each of the following has a better chance of influencing gene frequencies in small populations than in large populations, which one most consistently requires a small population as a precondition for its occurrence?
A. nonrandom mating
B. mutation
C. genetic drift
D. natural selections
E. gene flow

3.In modern terminology, diversity is understood to be a result of genetic variation. Which of the following is a recognized source of variation for evolution?
A. mistakes in translation of structural genes
B. recombination by crossing over in meiosis
C. binary fission
D. rampant changes to the dictionary of the genetic code
E. mistakes in protein folding