The factory was awarded the contract for the ______ with supplie

The factory was awarded the contract for the ______ with supplied drawings.
A、processing Gear Boxes
B、processings of Gear Boxes
C、processing of Gear Boxes
D、process of Gear Boxes
【正确答案】：C
【题目解析】：句意：该工厂获得了加工齿轮箱的合同，并提供了图纸。