A statistics professor used X = "number of class days attended" (out of 30) as an independent variable to predict Y = "score received on final exam" for a class of his students. The resulting regression equation was Y = 39.4 +1.4X. Which of the following statements is true? a. If attendance increases by 1.4 days, the expected exam score will increase by 1 point b. If attendance increases by 1 day, the expected exam score will increase by 39.4 points c. If attendance increases by 1 day, the expected exam score will increase by 1.4 points d. If the student does not attend at all, the expected exam score is 1.4