Final answer:
The safest way to transport a firearm in a vehicle is by keeping it unloaded, disassembled, or secured with a trigger lock or similar device, and storing it separately from ammunition.
Step-by-step explanation:
The safest way to transport a firearm in a vehicle is by keeping it unloaded and either disassembled or secured with a trigger lock or similar device, as required by law in many jurisdictions. This helps to prevent accidental discharge and unauthorized access to the firearm. Additionally, it is important to store the firearm separately from its ammunition, ideally in a secure container.