CleanCom Company specializes in cleaning commercial buildings and construction sites. Each building and site is different, requiring amounts and types of supplies and labor for each job. CleanCom estimated the following for the year:

Number of direct labor hours………………..5,110

Direct labor cost…………………………………$76,650

Overhead cost…………………………………….$45,990

During the year, the following actual amounts were experienced:

Number of direct labor hours………………..5,040

Direct labor cost…………………………………$75,600

Overhead cost……………………………………$46,200

If CleanCom uses a normal costing system and overhead is applied on the basis of direct labor hours, what is the cost of cleaning a construction site that takes $140 of direct materials and 21 direct labor hours?

a. $455

b. $508

c. $648

d. $644