Refer to the exhibit.
An OSPF neighbor relationship between R2 and R3 is showing stuck in EXCHANGE/EXSTART state.
The neighbor is established between R1 and R2. The network engineer can ping from R2 to R3 and vice versa, but the neighbor is still down. Which action resolves the issue?
A. Restore the Layer 2/Layer 3 conectivity issue in the ISP network.
B. Match MTU on both router interfaces or ignore MTU.
C. Administrative “shut then no shut” both router interfaces.
D. Enable OSPF on the interface, which is required.
