During the gasoline shortage of the 1970s caused by the actions of the

During the gasoline shortage of the 1970s caused by the actions of the OPEC nations, the number of accidents on our highways decreased markedly.

A) the number of accidents on our highways decreased markedly

B) the amount of accidents on our highways decreased markedly

C) there were less accidents on our highways

D) there were a fewer amount of accidents on our highways

E) they found there were many fewer accidents on our highways

1) Fewer vs. less
less is used for uncountable nouns
fewer is used for countable nouns

accidents are countable
less is wrong, eliminate option C

2) Amount vs. number
Amount is used for uncountable nouns
number is used for countable nouns

accidents are countable
Amount is wrong, eliminate option B and D

Between Options A and E
they in E have no antecedent, pronoun can't be without one.
Eliminate E

Answer is A