What is the UK’s currency?

The United Kingdom's currency is the British Pound Sterling, commonly represented by the symbol £. The Pound is one of the oldest currencies still in use today and has a long history that dates back to when it was originally defined as a unit of weight of silver.

Using the Pound allows the UK to maintain its own monetary policy and economic strategies, independent from the European Union and other international currencies. While the Euro is the currency used by many countries in the European Union, it is not the currency of the UK. The UK opted out of adopting the Euro and retained its own currency to exercise greater control over its economy.

Additionally, the US Dollar and the Australian Dollar are currencies associated with the United States and Australia, respectively, and are not used in the UK. Thus, the British Pound Sterling is the correct answer, as it is the legal tender that is used for all financial transactions within the United Kingdom.