The correct answer is multicast.
Unicast describes a packet sent from a single source to a single destination.
Broadcast describes a packet sent to all nodes on the network segment.
Anycast, refers to communication between any sender and the nearest of a group of receivers in a network.

Section: Software Development Security

Access is the ability to do something with a computer resource (e.g., use, change, or
view). Access control is the means by which the ability is explicitly enabled or
restricted in some way (Usually through physical and system-based controls).
Computer-based access controls can prescribe not only who or what process may have
access to a specific system resource, but also the type of access that is permitted.
These controls may be implemented in the computer system or in external devices.