Question

congress means :
a classification into two opposed parts or subclasses
a series with a definite pattern of advance
a collection of writings
a national legislative assembly

Explanation:

The word "congress" is most commonly used to refer to a national legislative assembly. For example, in the United States, the Congress is the legislative branch of the federal government. The other options do not accurately define the term "congress" in its most common usage.

Answer:

a national legislative assembly