QUESTION $23$

An $1-$O psychologist working in a large chain of retail stores develops a new training program to improve clerks' courtesy to customers. She measures the number of customer complaints before and after the training program is instituted. The independent frariable is $q,$ and the dependent variable is $q,$ the number of customer complaints; the training program the training program; the number of customer complaints clerks' courtesy to customers; the number of customer complaints the number of customer complaints; the clerks' courtesy to customers