You Want a Witness to Testify That He Saw a Stop

Multiple Choice

You want a witness to testify that he saw a stop sign at the scene of an accident when,in fact,no such sign exists.Which of the following questions would be most effective?

A) "Did you see a stop sign at the intersection?"
B) "Are you sure you didn't see a stop sign?"
C) "How fast was the white car going when it went through the stop sign?"
D) "Are there many stop signs in that neighborhood?"