Prime Costs = Direct Materials + Direct Labor ---> (4,680,000 = 2,220,000 + Direct Labor)
Direct Labor = 4,680,000 - 2,220,000 ---> (Direct Labor = 2,460,000)
Conversion Costs = Direct Labor + Overhead ---> (5,700,000 = 2,460,000 + Overhead)
Overhead = 5,700,000 - 2,460,000
Answer: E) Overhead cost is $3,240,000