What is the minimum participation requirement for the correct spinning positions in Group C?

The minimum participation requirement for the correct spinning positions in Group C is that at least half of the team must participate. This is an essential guideline to ensure that the majority of skaters are contributing to the performance, allowing for effective synchronization and cohesion within the group. In synchro skating, achieving a unified appearance is crucial, and having a significant portion of the team engaged in the spinning positions helps to demonstrate the team's skill and collective balance.

This requirement not only emphasizes the importance of collaboration among skaters but also reinforces the necessity of showcasing a well-rounded performance. When just half of the team participates, it allows for enough variety in the routines while still ensuring that a strong sense of teamwork and unity is presented to the judges.

The other options do not align with the specific standards for Group C. For instance, having all skaters participate may create challenges in maintaining the quality and complexity of the spin, while requiring only pairs or just one skater to participate would not fulfill the intent of demonstrating teamwork and synchronization that is vital in synchro skating performances.