1. The depression.sas7bdat data contains patients' depression level and quality of life level from INCPAD trial. There are 405 patients included in the dataset. Depression level was assessed using Hopkins Symptom Checklist (variable scl20), with higher scores reflecting more severe depression. Quality of life level was assessed using SF-12 questionnaire, and subscale of mental health was used here (variable mcs12), with higher scores reflecting better quality of mental health. The researchers are wondering whether quality of mental health is related to depression severity level (or, does depression severity level PREDICT quality of mental health?). Use the depression.sas7bdat data to complete the following: a. Download the data depression.sas7bdat from Canvas-Module 10 to your computer. b. Read this downloaded permanent SAS dataset (depression.sas7bdat) into SAS using data step (you can give your own dataset name). c. What is the explanatory variable? d. What is the response variable?