Which of the following statements regarding the features of blockchain technology are correct?1.Records stored in the database may be made visible to relevant stakeholders without risk of alteration.2.Copies of the entire database are stored on multiple computers on a network, syncing within seconds.3.Consortium blockchain is a blend of public and private blockchains allowing selective data access.4.Mathematical algorithms make it impossible to change or delete any data once recorded and accepted. Select the answer using the code given below:

1. A

   1 and 3

   This option claims that statements 1 and 3 are correct. However, statement 3 incorrectly defines a consortium blockchain in this context or is excluded from the correct set because statement 2 is also an essential valid characteristic of distributed ledger technology tested by UPSC here. Thus, this option is incorrect.

2. B

   2 and 4 only

   This option claims that statements 2 and 4 are correct while omitting statement 1. Statement 1 is indeed correct as blockchain records visibility can be granted securely to stakeholders without alteration risk. Thus, this option is incorrect.

3. C

   1, 2 and 4

   (c) 1, 2 and 4. Statement 1 is correct because data stored in a blockchain can be shared transparently with authorized stakeholders with cryptographic guarantees against tampering. Statement 2 is correct as decentralized networks maintain synchronized copies of the ledger across multiple nodes. Statement 4 is correct because once data is validated and added to a block, cryptographic hashing and consensus mechanisms render historical data immutable. Therefore, options 1, 2, and 4 form the correct combination.

4. D

   1 and 4 only

   This option claims that statements 1 and 4 are correct. It incorrectly omits statement 2, which accurately describes the decentralized multi-node architecture and rapid synchronization of blockchains. Thus, this option is incorrect. Summary. Official key is (c). Blockchain technology relies on decentralization, cryptographic immutability, and controlled transparency, making statements 1, 2, and 4 correct while other combinations fail.

Summary. Official key is (c). Blockchain technology relies on decentralization, cryptographic immutability, and controlled transparency, making statements 1, 2, and 4 correct while other combinations fail.