The major difference between the British and U.S. governments among the options provided is:
C. the leader of Britain is chosen by the legislature.
In the United Kingdom, the Prime Minister is typically the leader of the majority party in the House of Commons and is appointed by the monarch, while in the United States, the President is elected directly by the voters through the Electoral College system.
The other options are either true for both governments or not true of the British system, making option C the most accurate distinction.