Among the followings, __ is a discrete random variable, and __ is a continuous random variable. (i) The number of vehicles passing a traffic light in the next hour. (ii) The side (Head or tail) you get from tossing a coin. (iii) The revenue an automobile store makes tomorrow. (iv) The expected number of cars an automobile store sales tomorrow. O A. (iv); (i) O B. (ii); (iii) O C. (i); (iii) O D. (ii); (i)