Answer:
I think it's A) Always just answer the question the customer has.
Explanation:
I know it's not D) "Never look the customer in the eye."
I don't think it's C) "Always answer a question with another question" that just seems like it would be confusing for the customer.
And I don't think it's B) "Never try to get more information about what the customer needs" because part of you're job as a salesman is find out what the customer needs.
So that leaves answer choice A