Answer:
"I'm not sure... let me research it more.'
Explanation:
The ellipses consist of either three or four dots or periods. And a single dot means the ellipsis point, and if there is the omission of one or more words, then ellipsis consists of three dots(spaced). Hence, the correct option here is as mentioned above. And this is because there is a word omission, and that is being correctly described with the help of three dots.