what is the cause of this problem?

Click the Exhibit button. You have recently configured an IPsec VPN between an SRX
Series device and another non-Junos security device. The phase one tunnel is up but the
phase two tunnel is not present. Referring to the exhibit, what is the cause of this problem?

A.
preshared key mismatch

B.
mode mismatch

C.
proposal mismatch

D.
proxy-ID mismatch