The sports boosters club is having a bake sale to buy uniforms. They want to raise $250. They need to rent a booth for $20. How many dozen cookies will they need to sell if they charge $3 per dozen?

Which equation could be used to solve this problem?

A: 250 = 3 c - 20
B: 250 = 20 - 3 c
C: 250 = 3 - 20 c
D: 250 = 20 c - 3