premise: The United States dollar is used.
hypothesis: Dollar coin (United States) . The term silver dollar is often used for any large white metal coin issued by the United States with a face value of one dollar , whether or not it contains some of that metal . United States dollar . The United States dollar ( sign : $ ; code : USD ; also abbreviated US$ and referred to as the dollar , U.S. dollar , or American dollar ) is the official currency of the United States and its insular territories per the United States Constitution . Since the currency is the most used in international transactions , it is the world 's primary reserve currency . Several countries use it as their official currency , and in many others it is the de facto currency . Besides the United States , it is also used as the sole currency in two British Overseas Territories in the Caribbean : the British Virgin Islands and Turks and Caicos Islands .