In each of the following situations, is it more reasonable to simply explore the relationship between the two variables or to view one of the variables as an explanatory variable and the other as a response variable? In the latter case, which is the explanatory variable and which is the response variable?(a) The amount of time spent studying for a statistics exam and the grade on the exam(b) The weight in kilograms and height in centimeters of a person(c) Inches of rain in the growing season and the yield of corn in bushels per acre(d) A student's scores on the SAT Math test and the SAT Critical Reading test