关于引导定于从句中which和whose有点不理解.

关于引导定于从句中which和whose有点不理解.
You can tell the difference between a new car and one ____ engine has been repaired.
[A]which [B]whose
书上说只能选择whose,说是which只能引导主语或者宾语,不能做定语.
是说which只能引导一个句子,这个从句在整个句子中充当主语或者宾语.
还是说,which能引导一个先行词是主语或者宾语的句子?
这个one在句子中做什么成分?是不是也算宾语?我看有个and并列,和a new car是不是都算宾语?
偶只能自学.所以麻烦可能的话尽量讲细点.