What represents an appropriate description of a firearm's secure storage in a public space?

A firearm's secure storage in a public space is best described by being closed and locked in a trunk. This method provides the highest level of security by completely enclosing the firearm, thereby preventing unauthorized access. Locking the trunk not only keeps the firearm out of sight but also restricts access, which is crucial in maintaining safety in public areas.

Keeping the firearm secured in a closed trunk minimizes the risk of theft and accidental discharge, making it the preferred method for transporting firearms in a vehicle when not in use. In contrast, other choices like leaving a firearm exposed in a secured vehicle or in a gun rack inside the vehicle do not provide adequate security and could attract attention or lead to theft. Carrying a firearm openly can create risk and tension in public spaces, which is not advisable for safety and legal reasons. Therefore, secured storage in a trunk is the most responsible approach to firearm storage in a public environment.