What Is the Difference Between an "Accessible Population" and a "Target

What is the difference between an "accessible population" and a "target population"?

A) An accessible population meets inclusion criteria, whereas a target population meets exclusion criteria.
B) A target population meets inclusion criteria, whereas an accessible population meets exclusion criteria.
C) An accessible population represents the entire set of cases the researcher wishes to study, whereas a target population represents that part of the accessible population that could feasibly be included in the study.
D) A target population represents the entire set of cases the researcher wishes to study, whereas an accessible population represents that part of the target population that could feasibly be included in the study.