Which is not a type of natural selection

a. adaption
b. genetic variation
c. over stimulation
d. selection

i would say selection because this is not instinct thus not natural

significant amounts of nitrogen oxides, carbon monoxide, and other pollution

explanation:

passenger vehicles are a major pollution contributor, producing significant amounts of nitrogen oxides, carbon monoxide, and other pollution. in 2013, transportation contributed more than half of the carbon monoxide and nitrogen oxides, and almost a quarter of the hydrocarbons emitted into our air.

whats the answer to your question?