#### Solution By Steps***Step 1: Identify Blockchain's Security Source*** Blockchain's security primarily stems from its design, which is immutable and transparent. This means once data is recorded, it cannot be altered without altering all subsequent blocks and the network's consensus, making it secure.***Result:*** B. Its immutable and transparent nature***Step 2: Define Digital Signatures*** Digital signatures are a cryptographic technique used to authenticate and ensure the integrity of digital documents or messages. They confirm that a document has not been altered and verify the signer's identity.***Result:*** C. A way to authenticate and ensure the integrity of digital documents or messages using cryptography***Step 3: Explain DeFi*** DeFi stands for Decentralized Finance. It represents a shift from traditional, centralized financial systems to peer-to-peer finance enabled by decentralized technologies built on the Ethereum blockchain.***Result:*** B. Decentralized Finance#### Final Answer- Blockchain's security comes from: B. Its immutable and transparent nature- Digital signatures are: C. A way to authenticate and ensure the integrity of digital documents or messages using cryptography- DeFi is: B. Decentralized Finance#### Key ConceptBlockchain Security, Digital Signatures, DeFi#### Key Concept Explanation- **Blockchain Security:** Ensured by the immutable and transparent nature of blockchain technology, making it resistant to data alteration.- **Digital Signatures:** Cryptographic tools that authenticate the integrity and origin of digital messages or documents, ensuring security and trust.- **DeFi:** Stands for Decentralized Finance, a movement that leverages decentralized networks to transform old financial products into trustless and transparent protocols that run without intermediaries.
