Which of the following defines Proof-of-Stake the most? 1.A consensus mechanism to validate transactions and create new blocks that works by selecting validators in proportion to their quantity of holdings in the associated cryptocurrency. 2.Programs stored on a blockchain that run when predetermined conditions are met and are typically used to automate the execution of a contract. 3.A consensus mechanism that requires members of a network to solve an arbitrary mathematical puzzle in order to create a new group of trustless transactions (blocks) on the distributed ledger or blockchain. 4.The ability for a blockchain ledger to remain a permanent, indelible, and unalterable history of transactions..