Selected accounts with a credit amount omitted are as follows

Work in Process
Apr. 1	Balance	8,000	Apr. 30	Goods finished	X
30	Direct materials	55,300
30	Direct labor	191,200
30	Factory overhead	57,360

Finished Goods
Apr. 1	Balance	13,200
30	Goods finished	307,700

What was the balance of Work in Process as of April 30?

a. $13,200

b. $307,700

c. $4,160

d. $57,360