Answer:
a
Explanation:
If it is a definite noun, that is you are aware of it beforehand, you use the. If it is indefinite and begins with a vowel, use an. If it's indefinite and begins with a consonant, choose a.
1.7991
39.98-4.5%=38.1809
39.98-38.1809=1.7991
D. Ask listeners to change their personal values
Sorry if this is incorrect, but I believe it fits well with the conclusion.
B.) Where
The only answer that makes grammatical sense.