The answer is A.history of
The phrase <em>eating a peanut butter sandwich </em>is a gerund phrase, given that the word <em>eating </em>is a gerund.
They are sources that you can find the date, author, and have real facts and not just made up. Like if you went to the IRS website then that is a credible source for tax where as going to Wiki they are not credible because anybody can go there
