Mr. Aziz is a sculptor. He makes sculptures either out of bronze or out of steel. He charges $280 for each bronze sculpture he sells and $440 for cach steel sculpture he sells. Last year, he made 8 sculptures and sold all of them for a total of $2,400. How many bronze sculptures did Mr. Aziz make last year?
(A) 1
(B) 3
(C) 5
(D) 7