Which type of blockchain can reduce computational overhead and energy needs?

The correct choice is C, as permissioned blockchains are designed to limit access and participation to a select group of entities. This reduces computational overhead since only authorized nodes are able to validate transactions and create blocks. In a permissioned network, the consensus mechanisms can be more efficient compared to public blockchains, where every node participates in the validation process, potentially increasing both energy consumption and computational demand.

In a permissioned blockchain, the level of trust among participants allows for less complex consensus algorithms, such as Practical Byzantine Fault Tolerance (PBFT) or delegated proof-of-stake, which require fewer resources to operate. This streamlined validation process leads to lower energy needs and faster transaction processing, making permissioned blockchains particularly attractive for enterprise applications that must manage resources efficiently.

Public blockchains, in contrast, often rely on proof-of-work or similar mechanisms that involve extensive computation across numerous nodes, which contributes to higher energy consumption. Private blockchains, while somewhat more efficient, still may not achieve the same level of resource optimization as their permissioned counterparts, as they typically maintain some level of decentralized consensus among fewer validating nodes but may not limit participation as stringently. Hybrid blockchains, combining elements of both public and private systems, can also face similar challenges regarding