Portfast feature should only be used on edge ports (ports directly connected to end stations). Neither edge ports or PortFast enabled ports generate topology changes when the link toggles so we cannot say Portfast reduces the STP convergence time.
PortFast causes a switch or trunk port to enter the spanning tree forwarding state immediately, bypassing the listening and learning states so answer 'It immediately puts the port into the forwarding state when the switch is reloaded ' is the best choice.