The national legislature of the United States of America is officially known by which of the following names?

Introduction / Context:
Understanding comparative political systems is an important part of general knowledge and political science. The national legislature of each major democracy has a specific name that reflects its historical and constitutional traditions. In the United States of America, the central legislative body is bicameral, with two houses. This question asks for the official collective name of that national legislature. Being familiar with such basic terminology is useful for both international relations and comparative government topics in competitive exams.

Given Data / Assumptions:

• The subject is the national legislature of the United States of America.
• Four names are given: Commons, Congress, Parliament, and Senate.
• The learner must know which one is the official term for the entire legislative branch.
• Some options refer to just one chamber or to legislatures of other countries.

Concept / Approach:
The Constitution of the United States establishes a bicameral legislature consisting of the Senate and the House of Representatives. Together, these two bodies are collectively called Congress. The term Parliament is used for the national legislatures of many countries with the Westminster model, such as the United Kingdom and India, but not for the United States. The House of Commons is only one chamber of the British Parliament. The Senate is only one chamber of the United States Congress, not the entire body. Therefore, the correct concept is that Congress is the official name of the national legislature in the United States.

Step-by-Step Solution:

Step 1: Recall that the United States has a bicameral legislature with the Senate and the House of Representatives. Step 2: Remember that the collective name for these two houses is Congress. Step 3: Note that Commons is specific to the House of Commons in the United Kingdom and is not used in the United States system. Step 4: Recognise that Parliament is the term used for the central legislature in systems like the United Kingdom and India, but not for the United States. Step 5: Understand that the Senate alone is just the upper chamber of Congress, not the entire legislative branch, and therefore cannot be the correct answer.

Verification / Alternative check:
Verification is simple through any basic civics or international relations text, or even by recalling common phrases from news and media. Expressions such as United States Congress, members of Congress, and acts of Congress are widely used to refer to the legislative branch as a whole. In contrast, the term Parliament is never used in official American contexts for their national legislature. These repeated uses in global news and reference materials confirm that Congress is the established and correct term for the legislature of the United States of America.

Why Other Options Are Wrong:
Commons: This term refers to the House of Commons, which is one chamber of the Parliament of the United Kingdom, and has no official standing in the United States system. Parliament: This is the name for legislative bodies in countries such as the United Kingdom, India, and Canada, but it is not used to describe the American legislature. Senate: The Senate is only the upper house of the United States Congress and does not represent the entire legislature by itself. Since the question asks for the name of the national legislature as a whole, these three options are incorrect.

Common Pitfalls:
Some candidates may over generalise the term Parliament and think every democratic legislature is called by that name, which is not correct. Others may wrongly treat the Senate as synonymous with the entire legislative branch because it is often highlighted in news. To avoid such errors, aspirants should learn at least the basic legislative terminology of major countries, particularly the pairing Parliament with the United Kingdom and India, and Congress with the United States. This simple mental mapping is enough to handle common comparative polity questions like this one.

Final Answer:
The national legislature of the United States of America is officially known as the Congress.