The correct option of "2 and 3 only" is accurate because Bitcoins operate on a decentralized system known as blockchain, where transactions can be made pseudonymously. This means that while anyone can send or receive Bitcoins using a unique Bitcoin address, the identities behind those addresses remain hidden, allowing for anonymity in transactions (statement 3). However, Bitcoins are not tracked by Central Banks universally; they operate independently of traditional financial systems, meaning that statement 1 is incorrect. This decentralized nature of Bitcoin is a significant aspect in the study of digital currencies within the context of contemporary financial systems, making it relevant for examination in contexts like the UPSC Prelims.