Mason, Inc

Mason, Inc. uses a standard costing system. Overhead costs are allocated based on direct labour hours. The standard variable overhead and fixed overhead rates are $1 and $5 per direct labour hour, respectively. Data relevant for the current period include: Direct materials purchased 50,000 kg. @ $12 per kg.
Direct materials used 50,000 kg.
Standard quantity of direct materials
For actual production 45,000 kg.
Direct materials standard price $13 per kg.
Direct labour costs incurred 75,000 hours @ $12 per hour
Standard direct labour hours for
Actual production 78,000 hours
Standard direct labour cost per hour $11 per hour
Variable overhead costs incurred $77,070
Fixed overhead costs incurred $381,920
The cost of direct materials added to work in process would be:

A) $540,000
B) $585,000
C) $600,000
D) $650,000