Which of the following equations is used to calculate direct labor time variance? 

a. Direct labor time variance = (Actual direct labor hours + Standard direct labor hours) × Standard rate per hour 

b. Direct labor time variance = (Actual direct labor hours + Standard direct labor hours) × Actual rate per hour 

c. Direct labor time variance = (Actual direct labor hours – Standard direct labor hours) × Standard rate per hour 

d. Direct labor time variance = (Actual direct labor hours – Standard direct labor hours) × Actual rate per hour