At the end of Killo Co.'s first year of operations, 1,000 units of inventory remained on hand. Variable and fixed manufacturing costs per unit were $90 and $20, respectively. If Killo uses absorption costing, its net operating income would be higher than if it used variable costing by:

A) $0.

B) $20,000.

C) $70,000.

D) $90,000.