Which scenario would lead to a deduction for mounting on an unpermitted surface?

The scenario where a gymnast mounts on a carpeted area leading to a deduction for using an unpermitted surface is accurate because gymnasts are required to perform on specific, regulation surfaces as set forth by the governing bodies of gymnastics. Typically, permitted surfaces include competition mats, balance beams, and similar equipment designated for gymnastics performance. A carpeted area does not meet the necessary criteria for performance surfaces in competitive gymnastics due to concerns about stability and safety, making it an improper surface for mounting.

In contrast, the other scenarios do not inherently involve the violation of the permitted surface requirement. Using a wooden beam is an acceptable apparatus for events like balance beam routines. Landing improperly may incur deductions for execution errors but is not related to the surface on which the performance is occurring. Touching the floor without dismounting typically pertains to the rules about the completion of an exercise and not about the mounting surface, making it unrelated to deductions for surface violations.