Answer:
A. multiplying the standard quantity of direct labor by the standard price of direct labor.
Explanation:
Standard cost of direct labor = Standard quantity*Standard price. Standard cost of direct labor per hour are calculated and compared with the Actual cost of direct labor per hour and multiplied by Actual hours used to calculate direct labor rate variance.
So, option A (multiplying the standard quantity of direct labor by the standard price of direct labor) is correct.