What Is Administrative Distance?
http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094195.shtml
Administrative distance is the feature that routers use in order to select the best path. Administrative distance defines the reliability of a routing protocol. Each routing protocol is prioritized in order of most to least reliable (believable) with the help of an administrative distance value. Lowest Administrative distance will be chosen first.

The Router ID (RID) is an IP address used to identify the router and is chosen using the following sequence:
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The highest IP address assigned to a loopback (logical) interface.
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If a loopback interface is not defined, the highest IP address of all active router's physical interfaces will be chosen.
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The router ID can be manually assigned
In this case, because a loopback interface is not configured so the highest active IP address
192.168.0.1 is chosen as the router ID.

The question mentioned Boston router was not configured correctly or incomplete so we should check this router first. Click on Host B to access the command line interface (CLI) of Boston router.
Explanation:
Boston>enable (type cisco as its password here)
Boston#show running-config

First, remember that the current OSPF Process ID is 2 because we will need it for later configuration. Next notice that in the second "network" command the network and wildcard mask are 192.168.155.0 and 0.0.0.3 which is equivalent to 192.168.155.0 255.255.255.252 in term of subnet mask. Therefore this subnetwork's range is from 192.168.155.0 to 192.168.155.3 but the ip address of s0/0 interface of Boston router is 192.168.155.5 which don't belong to this range -> this is the reason why OSPF did not recognize s0 interface of Boston router as a part of area 0. So we need to find a subnetwork that s0 interface belongs to.
IP address of S0 interface: 192.168.155.5/30 Subnet mask: /30 = 1111 1111.1111 1111.1111 1111.1111 1100 Increment: 4 Network address (which IP address of s0 interface belongs to): 192.168.155.4 (because 4 * 1 = 4 < 5) Therefore we must use this network instead of 192.168.155.0 network Boston#configure terminal Boston(config)#router ospf 2 Boston(config-router)#no network 192.168.155.0 0.0.0.3 area 0 Boston(config-router)#network 192.168.155.4 0.0.0.3 area 0 Boston(config-router)#end Boston#copy running-config startup-config Finally, you should issue a ping command from Boston router to Lancaster router to make sure it works well. Boston#ping 192.168.43.1