Tom's Tug Boat Co. and Penelope's Port Services Inc. supply harbour towage services to the Port of London. They are considering entering into a secret collusive agreement to set the price per day to provide harbour towage services to the Port of London. Which of the following factors would make it most likely to be possible to sustain a collusive agreement?

A new supplier of harbour towage services to the Port of London, the Big Boat Co., has just entered the market.

The owners of Tom's Tug Boat Co. and Penelope's Port Services Inc. both put a low weight on achieving high profits in future time periods.

Neither Tom's Tug Boat Co. or Penelope's Port Services Inc can observe the price that the other firm offers to the Port of London to supply harbour towage services.

If either firm chooses to retaliate against the other firm 'cheating' on the agreement to collude, it will cause a large decrease in profits in future time periods for the firm that cheated.