Universal Chemical Manufacturers provides you the following cost data from its cost accounting department. Standard time to complete one unit: 24 minutes, Standard direct labour rate: OMR 12 per hour. During the month of April, 8,500 hours were worked and 20,000 units were manufactured. The actual direct cost is OMR 98,600. Compute labour efficiency variance. O a. 2500 Adverse O b. 3400 Favourable O c. None of these O d. 6000 Adverse