The correct answer is D. Snakes are the scariest animal because of their creepiness.
Explanation
Circular reasoning is a type of fallacy that is based on arguing a premise through particular premises that establishes the same idea of the first premise. According to the above, the sentence "Snakes are the scariest animal because of their creepiness" is an example of circular reasoning because it validates its statement through particular premises referred to the same ideas "snakes are the scariest animal" and "because of their creepiness" mean the same. So, the correct answer is D.