The correct answer to this open question is the following.
Although there are no options attached, we can say the following.
The most valid counter-argument to the description of the Mongols by the Russian duke was that the Mongols were interested only in plunder and treasure but not in controlling the Russian territory.
As we know by reading this part of history, the Mongols were terrible warriors that showed no mercy. They were fierce fighters that indeed were interested in destroying and plunder. And more than conquering and establish a form of government to rule a territory, by the way, they attacked and proceeded, it seemed that they were more interested in becoming wealthy.
The committees investigate and prepare legislation to be considered by the House. The committee is basically a sub-organization within the legislative branch, what it does is identify the issues for legislative review and recommend a course of action to the parent body after gathering information about the subject.