Can only the commander permit the wearing of brown/tan T-shirts?

The answer is that only the commander can permit the wearing of brown/tan T-shirts. This is because uniform regulations often designate specific authority to commanders concerning dress and appearance standards within the military or similar organizations. Commanders are responsible for maintaining order and discipline, and as part of this responsibility, they have the final say on what uniforms or variations thereof are permitted for their personnel.

The other choices indicate a broader authority that undermines the command structure. While officers may have some discretion, the overarching authority typically rests with the commander to ensure uniformity and adherence to regulations across the unit. This helps maintain a cohesive appearance and conveys a clear command hierarchy.