The correct answer is D. Everyone has the same chance of being part of the study
Explanation:
In research, especially in types of research that deal with human subjects, it is common the researcher does not study a complete population but selects a sample or portion of it that is used to draw conclusions about all the population. Additionally, a sample can be selected in many ways following specific criteria but in general terms random sample is recommended for many cases which implies the researcher select people to study randomly or by following methods without a pattern or criteria. In this way, the participants selected are more likely to represent all the population as researches do not select participants with only certain features but everyone has the same chance of being selected and this usually guarantees there is variety in the study. Therefore, the reason random sample is an effective way to select participants is that everyone has the same chance of being part of the study.