You are enabling OSPF on a router and notice that all the Fast Ethernet and the Gigabit Ethernet interfaces have the same OSPF cost of 1. Which single configuration change can you make in router ospf configuration mode so that the Fast Ethernet interfaces have a higher OSPF cost than the Gigabit Ethernet interfaces?
A . Change the OSPF interface cost globally.
B . Change the OSPF default metric.
C . Change the OSPF auto-cost reference bandwidth.
D . Change the OSPF administrative distance.
E . Change the OSPF metric type from E2 to E1.
Answer: C