Which of the following is NOT an example of cryptocurrency?

The correct choice highlights that PayPal is not a cryptocurrency. While Bitcoin, Litecoin, and Ethereum are all well-known forms of cryptocurrency, operating on decentralized networks using blockchain technology, PayPal is a digital payments platform. It enables users to send and receive money electronically but does not function as a cryptocurrency itself.

PayPal has integrated features that allow users to buy, hold, and sell cryptocurrencies, but it primarily serves as a broker rather than a blockchain-based currency. This distinction is crucial because cryptocurrencies are characterized by their use of cryptography for security and their operation on decentralized platforms, while PayPal is a centralized service that facilitates traditional currencies and transactions without the underlying principles of cryptocurrencies.