Step by step solution plz

[6] Gnat sells flaps at 2,000 each. These cost him 1,500, and selling expenses amount to 300/flap. He had no unsold flaps last year but 25 this year, and he had bought a further 40 flaps in the year. His net profit this year will be A 7,500 B4,500 C... 3,000 D... None of these