57. Forest Company, which uses a weighted-average process-costing system, had 7,000 units in production

at the end of the current period that were 60% complete. Material A is introduced at the beginning of

the process; material B is introduced at the end of the process; and conversion cost is introduced evenly

throughout manufacturing. Equivalent-unit production costs follow.

Material A: $12.50

Material B: $2.00

Conversion cost: $6.60

The cost of the company's ending work-in-process inventory is:

A. $88,620.

B. $115,220.

C. $123,620.

D. $147,700.

E. some other amount. I know answer is B but looking for how to solve it manually