Which of the following is a branch of the government?

The correct answer is based on the understanding that Congress is a key component of the legislative branch of the government in the United States. Congress, which consists of two chambers—the Senate and the House of Representatives—plays a crucial role in the legislative process, including making laws, regulating commerce, and overseeing the federal budget.

The Senate is indeed a part of Congress rather than a separate branch, and the House of Lords is specific to the United Kingdom's system of government, which is different from the U.S. structure. The Supreme Court, while it is one of the three branches of the U.S. government (the judicial branch), does not encompass the entire branch itself, as it is one institution within that branch. Therefore, when identifying a branch of the government in the context of the U.S. legislative framework, Congress is the most appropriate answer, as it represents the full legislative branch, including both the Senate and the House of Representatives.