Hi, "I want to get some juice, .....
a-want some? b-want some!
I think (b) is correct to indicate a question.
Hi, Ahmed.A.A—The answer choice is intended to be a truncated question: "[Do you] want some?" But the question should be preceded by a period or a dash:
- I want to get some juice. Want some?
- I want to get some juice—want some?