The correct answers are A and D. In IKEv1-based IPsec VPNs, there are two distinct negotiation phases. IKEv1 Phase 1 establishes the secure and authenticated IKE channel between peers. That means the IKE SA is built during Phase 1. Juniper describes Phase 1 as the negotiation of proposals for how to authenticate and secure the channel, including encryption algorithms, authentication algorithms, Diffie-Hellman group, and authentication method.

IKEv1 Phase 2 then uses that secure channel to negotiate the IPsec SAs that protect actual user traffic through the VPN. Juniper states that Phase 2 negotiates security associations to secure the data traversing the IPsec tunnel, and that the Phase 2 proposal includes the security protocol, such as ESP or AH, plus the selected encryption and authentication algorithms. Option B is wrong because IKEv1 SAs are not established in Phase 2; Phase 2 creates IPsec SAs. Option C is wrong because Phase 1 does not create the data-plane IPsec SA; it creates the secure IKE control channel used for Phase 2 negotiation. Reference topics: IPsec VPN, IKEv1 Phase 1, IKE SA, IKEv1 Phase 2, IPsec SA, ESP/AH proposals.