"What are you hoping to accomplish with that?"
This is particularly true when working with people who have a tangential relationship with the product. They have a problem, they think they know how to solve it, they start, and then they find a step they can't do. So you'll get a question about that step. Answering the question is great, but that's not their real goal.
So to be helpful, answer questions.
To be really helpful, understand the goal and then give a complete answer, which may or may not include answering the specific question.