Answer: The word with the positive connotation in this pair is "omit".
Explanation: The connotation of a word is the idea or the feeling that this word suggests. In that way, words can have a positive connotation or a negative connotation. A word with a positive connotation invokes a good or satisfying feeling; in contrast, a word with a negative connotation is associated with a negative or unpleasant feeling. The word with the positive connotation in the pair "neglect" vs. "omit" is "omit" since it invokes a good feeling, while "neglect" implies a negative feeling, mainly due to the fact that the action of neglecting is considered to be offensive.