Which two runtimes are contained within Peer Nodes?

The selection of endorsing and committing runtime as the correct answer reflects the fundamental operations that occur within peer nodes in a blockchain network.

In a blockchain context, peer nodes play a critical role in both the endorsement and the commitment processes of transactions. The endorsing phase involves nodes validating the transactions based on the current state of the ledger, thus generating endorsements that are necessary for a transaction to progress. These endorsements assure that the transaction proposal has been validated by multiple peers, enhancing trust among participants in the blockchain.

Once the endorsements are collected, the committing phase involves the consensus mechanism among the peer nodes to reach an agreement on the validity of that transaction. After consensus is achieved, the transaction can be committed to the ledger, making it a part of the blockchain history. This ensures that the state of the ledger is updated consistently across all participating nodes.

The distinction between endorsing and committing runtime is crucial because it reflects two integral operations that ensure transaction integrity and reliability in distributed ledger technologies. This separation is designed to promote scalability and fault tolerance within the network, laying the foundation for a robust and efficient blockchain system.