The correct explanation for why the shoe and the shirt take different amounts of time to fall to the ground is:
The difference in weight doesn't affect the time, but they are affected differently by air resistance.
In this case, the shoe and the shirt have different shapes and surface areas, which would lead to different amounts of air resistance acting on each object as they fall. While the acceleration due to gravity acts on both objects equally, the effects of air resistance can cause them to fall at different rates.