Tobin is having the basement remodeled. the contractor charges $16.50 per hour, plus the cost of supplies. the contractor goes to two different stores for supplies. at the first store the contractor spends $125.00 and at the second store the bill is $289.00. tobin gets a bill at the end of he project for $826.50. he thought the bill was going to be $701.50. which of the following explains the error tobin made? why?

a. tobin didn't include the bill for $289
b. tobin didn't include labor in the. amount
c. tobin didn't include the bill for $125
d. tobin didn't include either bill