I know this is a late answer, but hopefully it can help someone else out!
The answer to your question would be, "Each measure was voted on individually". This allowed congressmen to oppose the measures they disagreed with, but still keep the measures they agreed upon.
Answer:
A. Chinese
Explanation:
There was a law called the Chinese exclusion act.
Lincoln believed they committed acts of treason.
The idea is known as the Republican form. The idea is that people democratically elect those who would represent them in a government, and those people would be held accountable for what they've done if they do something opposite to the will of the people. It's the only way that a democracy can work properly because others would be impossible with that many people.