What characteristic of VLSM-capable routing protocols enables the use of different subnet masks against a single address class within a system?

Variable Length Subnet Masking (VLSM) allows routing protocols to utilize different subnet masks within the same address class by supporting the concept of subnetting at different levels. This characteristic enables efficient IP address allocation and management, as it allows networks to be divided into subnets of varying sizes based on specific needs, rather than being constrained to a single subnet mask. VLSM-capable protocols maintain routing tables that can accommodate multiple subnet masks, ensuring accurate and efficient route determination. This flexibility enhances overall network design and optimization.