Final answer:
Members of Congress, including senators and representatives, are mostly composed of upper-middle-class Americans.
Step-by-step explanation:
The correct answer to the question is: b) They are mostly upper-middle-class Americans.
Members of Congress, including senators and representatives, are mostly composed of upper-middle-class Americans. This can be seen in the fact that Congress is largely made up of white, wealthy men, and only a small percentage of Congress members are from minority groups or represent a single religion. While there has been some increase in the representation of racial and ethnic minorities in recent years, the overall composition of Congress does not accurately reflect the diversity of the United States population.
For example, despite more than half of the U.S. population being female, only 25 percent of Congress is female. Additionally, Congress is overwhelmingly Christian, further indicating the lack of diversity in religious representation.