37-40 Katrina Has Conducted a Study That Examines Entering Children's

Multiple Choice

37.-40. Katrina has conducted a study that examines entering children's social skills. She has first-grade teachers rate students' social skills at the end of first grade. She then compares the scores of students who attended formal Pre-Kindergarten programs with those who did not.
-What is the independent variable in Katrina's study?

A) Social Skills
B) First grade teachers
C) Pre-Kindergarten program
D) First grade