Explain how each of the following is a form of price discrimination:a. a student discount at the movie theater b. long-distance phone service that costs 15 cents per minute for the first 10 minutes and 5 cents per minute after 10 minutes. a senior citizen breakfast discount at a local restaurant. coupon discounts on laundry detergent 3.List three ways in which a grocery store might differentiate itself from its competitors. 4.Explain how the joint profit-maximizing price of colluding firms under oligopoly is determined? How about output?