Which of the following is a language for working with Ethereum?

Solidity is the primary programming language used for developing smart contracts on the Ethereum blockchain. It is a statically typed, high-level language similar to JavaScript and C++, and it is specifically designed for creating contracts that run on the Ethereum Virtual Machine (EVM). Key Details: Purpose of Solidity: Solidity was created by the Ethereum team to enable the development of smart contracts that automate the execution of blockchain-based applications. Its syntax is designed to be familiar to developers experienced in other programming languages, which helps in onboarding and learning. Compatibility and Flexibility: As a Turing-complete language, Solidity allows for the development of complex smart contracts and decentralized applications (DApps) with conditional logic, loops, and more. It is widely used in the DeFi space and beyond. Ethereum Test Networks: Other options listed, such as Rinkeby and Kovan, refer to Ethereum test networks where developers test smart contracts, but they are not languages themselves. Mist is an Ethereum wallet interface, not a programming language. Thus, C. Solidity is the correct answer, as it is the language specifically designed for working with Ethereum smart contracts.