Caldwell Manufacturing Company prepared a static budget of 120,000 direct labor hours, with estimated overhead costs of $480,000 for variable overhead and $90,000 for fixed overhead. The actual activity level was 110000 direct labor hours so Caldwell prepared a flexible budget at 110,000 labor hours. How much are total overhead costs at this flexible budget level of activity?
a. $480,000
b. $522,500
c. $530,000
d. $570,000