Which configuration parameter is missing at the hub to complete the configuration?

Refer to the Exhibit.

Referring to the exhibit, you are setting up the hub in a hub-and-spoke IPsec VPN. You have
verified that all configured parameters are correct at all sites, but your IPsec VPN is not
establishing to both sites.

Which configuration parameter is missing at the hub to complete the configuration?

A.
A different external-interface is needed for vpn1.

B.
A different st0 logical interface is needed for vpn2.

C.
Establish-tunnels immediately must be configured for vpn1.

D.
Multipoint needs to be configured under the st0.0 interface.