PLS HELP!!!

Casey earned $220 selling baked goods. Her expenses were $2.50 per baked good. Which equation can be used to find b, the number of baked goods Casey would have to sell in order to make a profit of exactly n$100?

a. 220 - 2.50b = 100

b. 220 + 2.50b = 100

c. 220b - 2.50 = 100

d. 220b + 2.50 = 100