我认为应该选A!楼主请三思!
in time与on time的区别
in time有"及时"的意思,意指正赶上时候或恰在需要的时候 要来不及了想要快点

on time是"准时;按时"之意.如交作业要按时交啦:

We were just in time for(或to catch) the bus.(我们及时赶上了公共汽车)
The train pulled in on time.(火车准时到站了)