The words "carefree" and "untroubled" are related in their denotation. Which choice explains their connotation?

They each have a positive connotation. They each have a positive connotation. One has a positive and the other a negative connotation.
They each have a neutral connotation. They each have a neutral connotation. They each have a negative connotation.

They each have a positive connotation.