There are several situations in which imagination can overcome reason.
One of the most common ones are when you're paranoid or you are fearful of something. In this case, your imagination starts creating the worst possible scenarios that can ever occur. However, when going through the situation itself, you will actually find that it is less terrifying than what you imagined and that your were just trapped in your imagination. <span />
Paired conjunctions
Either......or
Neither......nor
Not only.....but
Iwill go either to Rio or Bahia on my vacation
Neither John nor Mary speaks French
Not only does he speak French,but also German
The answer is C :) you need a comma