首先这道题有一点问题,talk是动词,不能直接作主语,因此这道题正确的题目可能有如下两种情况：
1、To talk to others with food in month is rude.
2、talking to others with food in month is rude.
第一种情况“to talk”作主语通常用形式主语代替
It is rude to talk to others with food in month.
第二种情况一般不倒装
所以正确答案为：
It is rude to talk to others with food in month.