Question: What action does the MM sublayer take when it receives the first CM message for an MM connection?
Option 1: It discards the message as it is not relevant to any existing MM connection.
Option 2: It distributes the message to the relevant CM entity and indicates that a new MM connection has been established.
Option 3: It sends a response back to the UE indicating that the MM connection is already established.
Option 4: It buffers the message until it receives further instructions from the CM entity.
Explanation: According to the specified behavior, when the MM sublayer receives the first CM message for an MM connection (identified by PD and TI), it not only distributes the message to the relevant CM entity but also indicates that a new MM connection has been established. This ensures proper handling of initial messages in establishing connections.