【答案】 B.to talk
不定式作宾语的复合结构就是不定式作句子宾语的补足语
当谓语是consider、find、think时,to be 可以省略
eg.I think it (to be)necessary for him to go there at once.
此句中
it 【宾语（形式宾语,真正的宾语是不定式to talk with talking with him ）】
to talk with talking with him 【这个不定式就是 it 的补足语了,构成了复合宾语】