SAT IE题又一道!

问题描述:

SAT IE题又一道!
Our new neighbors are the most(A) sociable people we have ever met(B),and our chief interestes(C),cooking and politics,are similar to them(D).No error (E)
D代指them为什么错?

前面对应的是our chief interests,用的是代词所有格,后面的代词也要用所有格形式,theirs