Answer: A
You can easily eliminate D, since King George never improved independence in the first place.
You can easily eliminate C, since Common sense was a pamphlet. There's no guaranteed that we know the exact number of pages it was. Even if we did know, that wouldn't be the reason Common Sense got so popular.
I don't think Common Sense was written in Latin. Even if it were, that shouldn't be the reason it got so popular.
Common Sense was a pamphlet that was published in 1776. It sold over 120,000 copies within 3 months, so that should have spread the word. The answer is A.