It is known that some naughty person out of these four people, Ace, Ben, Carl and Dan, took my sweets without my permission. I asked them who took my sweets and these are the responses:
Ace: Carl did not take the sweets.
Ben: I did not take the sweets.
Carl: I took the sweets.
Dan: Ace did not take the sweets.
If two of them lied and two of them told the truth, and only one of them took the sweets, then who is the culprit that took the sweets?!