Which action would resolve this issue?

A security administrator has configured an IPsec tunnel between two SRX devices. The
devices are configured with OSPF on the st0 interface and an external interface destined to
the IPsec endpoint. The adminstrator notes that the IPsec tunnel and OSPF adjacency keep
going up and down. Which action would resolve this issue?

A.
Increase the OSPF metric of the external interface.

B.
Create a firewall filter on the st0 interface to permit IP protocol 89.

C.
Configure the IPsec tunnel to accept multicast traffic.

D.
Create a /32 static route to the IPsec endpoint through the external interface.