Sarah's Soothing Diapers, Inc. and Orville's Odorless Diapers, Inc. are duopolists, who have agreed to collude. Orville has decided that he will comply with the collusive agreement as long as Sarah cooperated in the previous period. But if Sarah cheated in the previous period, Orville will punish Sarah by cheating in the current period. Orville's strategy is referred to as a

Find the answer in the attached as the system rejected the word

Explanation:

The strategy is a strategy adopted to get back at the other firm that  had committed a wrong in the first place.

This is more like reciprocating the actions of the other firm by cheating in the current period in response to the other firm that cheated in the previous period.

The origin of the strategy  means that this one that I done now is to repay you for that which you did earlier.

find attached as well.

answer; buying the bill at a discount from the face value to be received at maturity;