Which two statements about the multicast addresses query messages are true? (Choose
two.)

A.
They are solicited when a node initializes the multicast process.

B.
They are sent when a node discovers a multicast group.

C.
They are used to discover whether a specified multicast address has listeners.

D.
They are sent unsolicited when a node initializes the multicast process.

E.
They are used to discover the multicast groups to which listeners on a link are
subscribed

F.
They are usually sent only by a single router on a link

Explanation:
Query message sent by the multicast routers can be one of three forms:
General Query – group address and source address fields are zeroGroup-Specific Query – group address field contains the group address, whereas the address fields are zero
Group-and_Source-Specific Query – group address field contains the group address, and
the source address fields contain the sources that are emanating the multicast streams