Willis Company had a net operating income of $75,000 using variable costing and a net operating income of $57,000 using absorption costing. Variable production costs were $15 per unit. Total fixed manufacturing overhead was $120,000 and 10,000 units were produced. During the year, the inventory level was:

A) A) increased by 1,200 units.

B) increased by 1,500 units.

C) decreased by 1,500 units.

D) decreased by 1,200 units.