The Federal Republic of Germany (FRG) was formally established in

Primary sources do not need to be verified when using them as sources for a social research study

Indicate whether the statement is true or false

High school students from low-income families sometimes work after school to bring in extra income. Because of the hours they spend working, they have less time to do homework, which can lead to poorer grades. A researcher explores the effect of family income on grades. What type of variable is working part time in this study?

A. Common cause B. Intervening variable C. Control variable D. None of the above