The best answer is minority groups (racial groups would work too, but only if physical characteristics are mentioned, but not for cultural practices).
Minority groups are often discriminated: treated unfairly.
b) the preservation of the United States and its democratic system
Lincoln wanted to preseve the nation
The correct answer that best describes the rule of law is option B. The process of setting precedent through the different levels of the courts.
Because the rule of law tells us that all activities carried out must be guaranteed by law.