Refer to the exhibit. What does router R1 use as its OSPF router-ID? 

Answer options:

A. 10.10.1.10
B. 10.10.10.20
C. 172.16.15.10
D. 192.168.0.1

C

OSPF uses the following criteria to select the router ID: 1. Manual configuration of the router ID (via the router-id x.x.x.x command under OSPF router configuration mode). 2. Highest IP address on a loopback interface. 3. Highest IP address on a non-loopback and active (no shutdown) interface.