The correct answer is: There is a little water in the cup, isn't there?

Explanation: Only if there are negative words in the sentence before the comma, do not use negative words in the sentence after the comma. form. And you have to distinguish between the two words a little and little. The former means "some" means affirmation, and the latter means "almost none" means negation. For this question, a little is an affirmative word, so I choose isn't.

Are you stand?