What equation would you use to solve this problem?

Drake spent $150 to build a pumpkin pie stand and sells pumpkin pies for $5 each. One Direction spent $130 to build their pumpkin pie stand and sells pumpkin pies for $3 each. How many pies would have to be sold for them to have the same amount of money?

a. 5x - 150 = 3x + 130
b. 150 - 5x = 130 - 3x
c. 5x - 150 = 3x - 130