Final answer:
The libero cannot be designated as the team captain on the line-up sheet because the role of the libero is focused on defensive skills, while the team captain represents the team and makes strategic decisions.
Step-by-step explanation:
No, the libero cannot be designated as the team captain on the line-up sheet. The libero is a specialized position in volleyball that focuses on defensive skills, and they have certain restrictions and privileges during the game. However, the team captain is typically a player who provides leadership and represents the team on and off the court. This role is usually given to a player who has a deeper understanding of the game and can make strategic decisions for the team.