Parturition refers to the delivery of offspring

What is the most common lifestyle disease today.

Why would a researcher want to ensure that every person in the underlying population of study has an equal chance of being included in the sample?

A. It helps eliminate a correlational relationship. B. It increases the chances of finding a causal relationship. C. It provides important epidemiological information, such as the prevalence and incidence of the disorder. D. It increases the researcher's ability to generalize findings to the larger group.