Dr. Farah is an educational psychologist who is interested in studying the link between homework and academic achievement. Over the years, several researchers have found a link between the two, suggesting that doing homework is associated with higher grades. However, Dr. Farah is curious about the possible causal link between the two variables. She conducts the following study. At the beginning of the spring semester, Dr. Farah measures the number of hours her students spend doing homework during the preceding week and their fall GPA (a measure of academic achievement). At the end of the semester, Dr. Farah measures the same variables again (the hours spent doing homework the preceding week and their spring GPA). She finds the following correlations. Variable A Variable B Correlation Coefficient Correlation A Fall Number of Hours of Homework Fall Semester GPA .83* Correlation B Spring Number of Hours of Homework Spring Semester GPA .80* Correlation C Fall number of hours of homework Spring Semester GPA .69* Correlation D Fall number of hours of homework Spring number of hours of homework .36* Correlation E Fall semester GPA Spring number of hours of homework .18 Correlation F Fall semester GPA Spring semester GPA .45* *indicates a significant correlation Refer to the study above to answer the question. In considering the three causal rules, which of the following rules/questions will Dr. Farah’s study address?