Explanation/Reference:
Section: Addressing and Routing Protocols in an Existing Network Explanation Explanation:
Internal Border Gateway Protocol (iBGP) routes are assigned an administrative distance (AD) of 200 by default. AD values are used to determine the routing protocol that should be preferred when multiple routes to a destination network exist. A routing protocol with a lower AD will be preferred over a route with a higher AD. The following list contains the most commonly used ADs:

External BGP (eBGP) routes are assigned an AD of 20 by default. Routes to networks in other autonomous systems (ASes) are called interdomain routes. Interdomain routes typically exist only on routers that border an AS. Therefore, if multiple routes to an external network exist in the routing table, the router should use the route advertised by an interdomain routing protocol, such as eBGP, over the route advertised by an intradomain routing protocol, such as Open Shortest Path First (OSPF).
Directly connected routes have an AD of 0. Therefore, directly connected routes are trusted over routes from any other source. Static routes have an AD of 1. Like directly connected routes, static routes are more trusted than routes from any routing protocol. Static routes are optimal for routing networks that do not change often.
Routes that are learned by Interior Gateway Routing Protocol (IGRP) have an AD of 100 by default.
Routes advertised by an interior routing protocol, such as IGRP, are typically intradomain routes.
Reference:
CCDA 200-310 Official Cert Guide, Chapter 10, Administrative Distance, pp. 386-387 Cisco: What Is Administrative Distance?