Using the provided topology and show command output, it can be determined that L3-SW-2 in the Branch Office does not have a route to reach the subnet where PC1 resides (192.168.1.0/24 in the HQ Office). L3-SW-1 in the HQ Office has a route to the Branch Office subnet (172.16.1.0/24), but without the reciprocal route on L3-SW-2, traffic from the Branch Office will not be able to reach the HQ Office subnet, hence PC1 cannot ping PC2.