host 1 and the switch are on same subnet, vlan 1, 172.19.1.0/24,
and host 2 is on diff subnet,
so, if intervlan routing is configured, host 2 can ping host 1, then there might be an ACL configured either on switch or on the router preventing telnet traffic to switch from host B.
also, i doubt that host 2 can ping host 3, if IP addresses are same as shown in diagram
host 3 belongs to 172.19.3.0/24 and vlan 33 on router is 33.0/24.