Specifying the Research Population Is Important for All of the Following

Specifying the research population is important for all of the following reasons except:

A) the research population influences the generalizability of the eventual results
B) the research population influences the number of observations that can be included in the dataset
C) the research population is the set of all possible observations based on a particular characteristic within a particular unit of analysis
D) the researcher should pick a sample partially outside the research population to have a control