Refer to HW#4 Article#1 "Whirlpool cleans up its supply chain". Which of the following is most relevant to it? Question 15 options: a) Whirlpool opened a new Product Development Center (PDC), which promotes the sharing of ideas to develop better products. b) The keiretsu system helped Whirlpool become one of the most successful companies in the global market for consumer appliances. c) Production leveling was vital to the success of a merger with Maytag. d) A merger with Maytag further complicated Whirlpool's efforts to manage the supply chain