I've never understood this line of questioning. Your firearm has nothing to do with the traffic stop unless you are in an overbearing state that has so trampled on your rights that you are forced to tell the officer about the legal possessions that are on you in your car without a warrant. The traffic stop is about one thing, whatever traffic violation you have committed.
If the conversation between you and the officer goes in any other direction, you have the right to remain silent and you have right against self-incrimination. Shut up or say, I do not answer questions without my lawyer.
A police officer can ask you anything. You do not need to answer him. Your legal firearm shouldn't even be associated with the traffic stop.