You want to implement a hub-and-spoke VPN topology using a single logical interface on the hub.
Which st0 interface configuration is correct for the hub device?

A.
[edit interfaces]
user@srx# show
st0 {
multipoint
unit 0 {
family inet {
address 10.10.10.1/24;
}
}
}

B.
[edit interfaces]
user@srx# show
st0 {
unit 0 {
family inet {
address 10.10.10.1/24;
}
}
}

C.
[edit interfaces]
user@srx# show
st0 {
unit 0 {
point-to-point;
family inet {
address 10.10.10.1/24;
}
}
}

D.
[edit interfaces]
user@srx# show
st0 {
unit 0 {
multipoint;
family inet {
address 10.10.10.1/24;
}
}
}

Explanation:

Reference: http://junos.com/techpubs/en_US/junos12.1/topics/example/ipsec-hub-and-spokeconfiguring.html