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.
a) No, because the researcher did not measure what he claimed to measure (the relationship between cancer and stress levels)
b) Yes, because the researcher changed his focus based on valid responses from participants
c) Yes, because the researcher did have a result in the end that showed there was some relationship between two variables.
d) No, because a relationship between variables can only be determined by an experiment
The Supreme court maintained a precise separation of state power and national power
If the likelihood of each possible outcome does not change from trial to trial
