What is the economic mechanism assuring that the consensus mechanism works so that all miners would find it optimal to add a valid block in their own copy of the blockchain? a. The system automatically updates the ledger b. Adding a valid block candidate in their blockchain is a dominant strategy for all participants in the network c. The communication among miners and the idea that such a strategy is a Nash equilibrium assure it d. The consensus mechanism works because of cryptography and does not have any economics behind