ADT Ltd. has furnished the following standard cost data per unit of output. Direct labor 10 hours at Rs7.50 ,Rs 75. Direct wages paid Rs 4,07,000 for 55,000 hours worked per hour at Rs 8.50 per hour Rs 85. Actual output 4,900 units. The labor efficiency variance is: a) Rs 50,000 favorable b) Rs 55,500 (favorable) c) Rs 35,000 (Adverse) d) Rs 45,000 (Adverse)