Fastflix and WatchNow are the only two companies that sell movie and TV streaming subscriptions. For several years, Pastflix priced its subscriptions below average variable cost. WatchNow tried to compete by also selling subscriptions below average variable cost, but went bankrupt and exited the market. Several months after WatchNow exited the market, Fastflix raised prices by $40\%$ and is currently earning large, positive economic profits. Based only on this information, an argument can be made that Fastflix engaged in

predatory pricing.

collusion.

illegal backward induction.

mutual interdependence.

tit$-$for$-$tat.