According to MLA format do I have to site factual information if I did not look it up, I just knew it?

warren buffett- the oracle of omaha warren buffett came from a normal type of family in nebraska. when hew as young, he understood the value of investing money and gaining interest on that investment. he strived hard at several jobs, but what made him one of the wealthiest men in the world was his gift for allocating capital within a free market system. warren buffett is an example of a man whose wealth is owed largely to the free enterprise system. buffett was able to allocate his money however he wanted, investing in businesses that he thought could compete effectively. without the free market system, he would not have the right to invest however he wanted, and would not have become so wealthy.

the answer is b. my dude