Question: Upon receiving a Floor Taken message with the first bit in the subtype set to '1', what action should the Interworking Function (IWF) floor participant take regarding the Message Type field in the subsequent Floor Ack message?
Option 1: Set the Message Type field to '1' (Floor Request)
Option 2: Set the Message Type field to '2' (Floor Taken)
Option 3: Set the Message Type field to '0' (Reserved)
Option 4: Omit the Message Type field
Explanation: When the first bit in the subtype of the Floor Taken message indicates that an acknowledgment is required, the IWF floor participant must respond with a Floor Ack message. According to the specifications for handling such messages, the Floor Ack message should include the Message Type field set to '2', which corresponds to "Floor Taken". This ensures proper signaling and acknowledgement in the media plane control interworking between MCPTT and LMR systems, maintaining the integrity of floor control procedures.