What is the currency used in the United Kingdom?

The currency used in the United Kingdom is the Pound Sterling, often simply referred to as the pound. This currency has a long history and is one of the oldest currencies still in use today. The pound is represented by the symbol £ and is subdivided into 100 pence. It serves as the primary medium of exchange within the UK and is also used in some of its territories.

In contrast, the euro is the official currency for many countries in the European Union but is not used in the UK, as the UK opted to maintain its own currency. The dollar is commonly recognized in several countries (like the US) but does not play a role in the UK's economy. The franc, which was used in several European nations (such as France and Switzerland), is no longer in widespread circulation in its original form, having been replaced primarily by the euro. Therefore, the Pound Sterling is the correct answer as it signifies the unique monetary identity of the United Kingdom.