57. Are there any reference cells in this problem? If so, what are they? a. No, there are no reference cells. b. Yes, reference cells are high CAT, ever smoked, abnormal ECG, and high BP. c. Yes, reference cells are normal CAT, never smoked, normal ECG, and not high BP. d. Yes, reference cells are higher age, higher cholesterol, higher DBP, and higher SBP. e. Bothb and d f. Both c and d