Your network has a mixture of Fast Ethernet and Gigabit Ethernet links. What needs t o be done to ensure optimal data routing when using OSPF?（）

• A、Nothing. OSPF will determine the most optimal path for routing data by default.
• B、Adjust the hello and dead timers for more rapid detection of link failures.
• C、Increase the reference - bandw idth used to calculate the interface default metrics, on all routers in your network.
• D、Set the priority values on every broadcast interface to ensure that the designated and backup designated routers are the routers with the most processor and memory  resources.