What does a punch-down block ensure in a network setup?

A punch-down block is a crucial component in network setups, particularly for organizing and connecting multiple network cables. Its primary function is to provide reliable connections for network cables, which is essential for ensuring that signals are transmitted accurately across the network. When cables are punched down into the block, they are securely connected to specific terminals. This not only helps maintain the integrity of the signal but also simplifies the organization of cables, making troubleshooting and management easier.

The reliability of connections is vital in a network environment, as unstable or improperly connected cables can lead to data loss, network interruptions, and overall degraded performance. The punch-down block effectively minimizes these risks by providing a structured and stable arrangement for the cables, which is why option C is the correct answer in this context.