Which of the following best captures the idea of kaizen? (a) Examples of this include workers having to make unnecessary movements (i.e., excessive reaching or walking to get tools or parts), working on parts that are defective, and idle time. (b) A system that enables a line worker to signal that he or she needs assistance from his or her supervisor-for example, in the case of a defect. It is used to implement the jidoka principle. (c) A brainstorming technique that helps structure the process of identifying underlying causes of a (usually undesirable) outcome. (d) As an example of this philosophy, workers in the factory have notebooks at their workstations that they use to jot down improvement ideas. (e) A method that controls the amount of work-in-process inventory. (f) If an automotive assembly plant used this technique, the adjacent cars on an assembly line would be mixed models (e.g., Model A with sunroof, Model A without sunroof, Model B, Model B with sunroof) in proportions equal to customer demand