Final answer:
The statement is false because an ACL typically needs to specify both the source and destination, including for directed broadcasts which require the subnet as the destination to be specified.
Step-by-step explanation:
The statement is false. A router's Access Control List (ACL) typically needs to define both the source and the destination of the traffic to control. A directed broadcast is a packet that is sent to all hosts on a specific subnet, which means the ACL needs to specify the subnet as the destination if the aim is to control such traffic. To control directed broadcasts, a router's ACL might include the network address and subnet mask to identify the subnet as the destination. This way, the router can permit or deny the incoming or outgoing traffic to that specific subnet.