We went to _1_ grocery store to see if there was __2__ apple pie to purchase __3__ enjoy.

which word is used correctly in blank #2?

a. a
b. an
c. and

We went to a grocery store to see if there was an apple pie to purchase and enjoy.

An is the correct answer as before any word starting with vowel we use an and not a ...so an must be used in the sentence and after completion sentence will be

we went to *a*grocery store to see if there was **an**apple pie to purchase *and* enjoy

In 1987 a meeting was held in Montreal where twenty-four representatives from 24 nations participated. They agreed and signed “Montreal Protocol on Substances” which represented an agreement to reduce the production and usage of CFCs.

Chlorofluorocarbons (CFCs) are nontoxic, nonflammable chemicals containing particles of carbon, chlorine, and fluorine. They are utilized as a part of the produce of airborne splashes, blowing operators for froths and pressing materials, as solvents, and as refrigerants. They cause the reduction or thinness of Ozone layer.