Explanation:

Both statements 2&3 are correct.

• A blockchain is a form of Decentralised distributed database or ledger that is shared among the nodes of a computer network.
• The innovation of a blockchain is that it guarantees the fidelity and security of a record of data and generates trust without the need for a trusted third party.
• Estonia, the world’s blockchain capital, is using blockchain infrastructure to verify and process all e-governance services offered to the general public.
• Blockchains are best known for their crucial role in cryptocurrency systems, such as Bitcoin, for maintaining a secure and decentralized record of transactions. 

Hence option 2nd is correct.