Safeflower Systems allocates manufacturing overhead based on machine hours. Each connector should require 8 machine hours. According to the static budget, Safeflower expected to incur the following:

400 machine hours per month (50 connectors * 8 machine hours per connector)

$4000 in variable manufacturing overhead costs

$6210 in fixed manufacturing overhead costs

During August, Safeflower actually used 500 machine hours to make 120 connectors and spent $5000 in variable manufacturing costs and $7200 in fixed manufacturing overhead costs. SafeFlower's predetermined standard variable manufacturing overhead rate is

a. $8 per machine hour

b. $15.53 per machine hour

c. $10 per machine hour

d. $25.53 per machine hour