Explanation/Reference:
Section: Addressing and Routing Protocols in an Existing Network Explanation Explanation:
The Enhanced Interior Gateway Routing Protocol (EIGRP) route is used when the link to the static route goes down. EIGRP is a Cisco-proprietary routing protocol. When multiple routes to a network exist and each route uses a different routing protocol, a router prefers the routing protocol with the lowest administrative distance (AD). The following list contains the most commonly used ADs:

In this scenario, the static route has the lowest AD. Therefore, the static route is used instead of the other routes. When the static route fails, the EIGRP route is preferred, because internal EIGRP has an AD of 90.
If the EIGRP route were to fail, the Interior Gateway Routing Protocol (IGRP) route would be preferred, because IGRP has an AD of 100. If the IGRP route were also to fail, the Open Shortest Path First (OSPF) route would be preferred, because OSPF has an AD of 110. The Routing Information Protocol version 2 (RIPv2) route would not be used unless all of the other links were to fail, because RIPv2 has an AD of 120.
ADs for a routing protocol can be manually configured by issuing the distance command in router configuration mode. For example, to change the AD of OSPF from 110 to 80, you should issue the following commands:
RouterA(config)#router ospf 1
RouterA(configrouter)#distance 80
You can view the AD of the best route to a network by issuing the show ip routecommand. The AD is the first number inside the brackets in the output. For example, the following router output shows an OSPF route with an AD of 80:
Router#show ip route
Gateway of last resort is 10.19.54.20 to network 10.140.0.0
E2 172.150.0.0 [80/5] via 10.19.54.6, 0:01:00, Ethernet2
The number 5 in the brackets above is the OSPF metric, which is based on cost. OSPF calculates cost based on the bandwidth of an interface: the higher the bandwidth, the lower the cost. When two OSPF paths exist to the same destination, the router will choose the OSPF path with the lowest cost.
Reference:
CCDA 200-310 Official Cert Guide, Chapter 10, Administrative Distance, pp. 386-387 Cisco: What Is Administrative Distance?