Question: Upon receiving a Floor Release message with Acknowledgment required, what action(s) must the IWF floor control server take towards the MCPTT client?
Option 1: Send only a Floor Idle message with an incremented Message Sequence Number.
Option 2: Send a Floor Ack message and then transition to 'U: not permitted and Floor Idle' state without further actions.
Option 3: Send a Floor Ack message with specified fields (Message Type set to '4', Source set to '2') and then send a Floor Idle message, also checking for queued floor requests based on the Track Info field or SSRC.
Option 4: Ignore the Acknowledgment requirement and only check for queued floor requests to remove if present.
Explanation: When the first bit in the subtype of the Floor Release message is set to '1', indicating Acknowledgment is required, the IWF floor control server must respond with a Floor Ack message that includes specific details (Message Type set to '4' and Source set to '2'). Additionally, it needs to send a Floor Idle message while also handling potential queued floor requests based on the presence of a Track Info field or using the SSRC. This comprehensive response ensures both acknowledgment and state management are properly handled.