You have been asked to establish a dynamic IPsec VPN between your SRX device and a remote user.
Regarding this scenario, which three statements are correct? (Choose three.)

A.
You must use preshared keys.

B.
IKE aggressive mode must be used.

C.
Only predefined proposal sets can be used.

D.
Only policy-based VPNs are supported.

E.
You can use all methods of encryption.

Explanation:
http://kb.juniper.net/library/CUSTOMERSERVICE/GLOBAL_JTAC/technotes/dynamic-vpnappnote-v12.pdf