Router 2
Router 2 picks up the packet destined for its MAC address and strips off the Network Interface information.
Router 2 analyzes the IP Header destination address and identifies that it is destined for network 192.168.4.0. Next, Router 2 checks its routing table.
According to its routing table, Router 2 should use interface 192.168.3.1 to get to Router 3 for traffic going to network 192.168.4.0.
Router 2 repackages the Network Interface layer of the packet adding the MAC address for Router 3 to the packet. The destination IP address remains 192.168.4.22 and the data packet is sent to Router 3.