When asked why he went there, he said he was sent there ______fo

When asked why he went there, he said he was sent there ______for a space flight.
A、training
B、being trained
C、to have trained
D、to be trained
【正确答案】：D
【题目解析】：句意为：当被问及他去那儿的原因时，他说到时为了训练太空飞行
动词不定式表目的且主语和谓语为被动关系。D选项符合