Which of the following optional features allow ports to move directly to a forwarding state in RSTP?

The feature that allows ports to move directly to a forwarding state in Rapid Spanning Tree Protocol (RSTP) is PortFast. PortFast enables a port that is connected to an end station, such as a computer or printer, to skip the listening and learning states and transition immediately to the forwarding state. This is particularly useful in environments where devices frequently connect and disconnect, as it reduces the time needed for a connection to become active.

While BackboneFast and UplinkFast enhance the stability and responsiveness of a network by optimizing route changes, they do not allow ports to transition directly to the forwarding state. BackboneFast helps to quickly respond to topology changes by discovering alternative paths, while UplinkFast enables rapid link recovery by promoting backup links if the primary link fails. Neither of these features modifies the state transition behavior for individual ports in the same way that PortFast does.

In conclusion, while all three options improve network performance and recovery, only PortFast specifically allows for that direct movement to the forwarding state in RSTP, making it the key feature in this context.