Answer: B. Population.
Explanation: Population may be explained from a statistical view to consist or incorporate all individuals or participants who is eligible and fits a certain research criteria within the research setting. For instance, a population of college students in New York city should consists of all students attending colleges in the New York. Hence it can be deduced that, population is a set of all eligible participants. It is from these population that sample is being drawn from which is a random subset of participants which is representative of the entire population.
Mandela means that someone who decides to take someone else's freedom is prjudiced and narrowminded. He can not be free if he takes away someone else's freedom just as a person who does not have freedom.
A person who takes away someone else's freedom is not free.