Iris Souza Started the Summer with $30

Iris Souza started the summer with $30.She took $10 and made signs for her dog walking service.She posted the signs all over her neighborhood.She used the other $20 to buy a stout leash and a pooper-scooper.At the end of the summer, after buying herself a new pair of shoes for $50 (she had worn her other shoes out walking dogs) , she had $125 left.Calculate Souza's costs for her summer job?

A) $30
B) $50
C) $80
D) $125
E) $175