Favian received a $100 gift card to a clothing store. Using only the gift card, he was able to purchase (n) sweaters that cost $32 each and 1 belt for $20. If there was no tax on the sweaters and belt, which of the following must be true?
a) 80 ÷ n ≥ 32
b) 32 ÷ n ≥ 80
c) 80 ÷ n ≤ 32
d) 100 - 32n ≤ 20