Sally is buying paper clips and staples for the office. A box of paper clips costs (x) $2, and a box of staples (y) costs $4. She is using only the petty cash account's balance of $28 to make the purchase. Which inequality models this situation?
A) 2x + 4y ≤ 28
B) 4x + 2y ≤ 28
C) 4x + 2y < 28
D) 2x + 4y > 28