Explanation/Reference:
Explanation:
Access list 2 is more specific, allowing only 1.2.3.0/24, whereas access list 1 permits all 1.0.0.0/8 networks. This question also asks us to apply this distribute list only to the outbound direction of the fast Ethernet 0/0 interface, so the correct command is "distribute list 2 out FastEthernet0/0."

Explanation/Reference:
The key to this question is the four terminology about DUAL. Enhanced Interior Gateway Routing Protocol (EIGRP) is an enhanced distance-vector protocol based on the diffusing update algorithm (DUAL). It is capable of (conservatively) finding all loop-free paths to any given destination based on route advertisements from neighbors. The neighbor (or neighbors) with the best path to a destination is called the successor. The remaining neighbors with loop-free paths to the destination are called feasible successors. To reduce traffic load on the network, EIGRP maintains neighbor relationships and exchanges routing information only as needed, using a query process to find alternate paths when all loop-free paths to a destination have failed.

Explanation/Reference:
Explanation:
The standby track command allows you to specify another interface on the router for the HSRP process to monitor in order to alter the HSRP priority for a given group. If the line protocol of the specified interface goes down, the HSRP priority is reduced. This means that another HSRP router with higher priority can become the active router if that router has standby preempt enabled. Loopback interfaces can be tracked, so when this interface is shut down the HSRP priority for that router will be lowered and the other HSRP router will then become the active one.
Reference: http://www.cisco.com/c/en/us/support/docs/ip/hot-standby-router-protocol-hsrp/13780-6.html

Distribute list are used to filter routing updates and they are based on access lists. In this case, an access list of 44 was created to deny the route from network 172.16.1.0/24 so this route will not be entered into the routing table of RTA. But the route from RTW can be entered because it is not filtered by the access list A and B are not correct because the distribute list is applied to the inbound direction of interface BRI0 so outgoing routing updated will not be filtered.
Distribute list just filters routing updates so user traffic from network 172.16.1.0 will not be denied.