Four consumers each want to buy a refrigerator. Without a retail intermediary like Best Buy, fridge manufacturers Walton, Sub$-$Zero, Bosch, Kenmore, and General Electric would each have to make four contacts to reach the four consumers who are in the target market, for a total of twenty transactions. But when Best Buy acts as an intermediary between the producer and consumers, each producer needs to make only one contact, reducing the number to nine transactions. This is an example of a $\_\_\_\_\_\_.$

Question $3$ Select one:

a$.$

manufacturer using additive manufacturing

b$.$

retailer using contract logistics

c$.$

manufacturer offering exchange utility

d$.$

retailer offering contact efficiency