question: What is a Downlink Pilot Timeslot? option 1: The part of the special subframe designated for uplink transmission. option 2: The part of the special subframe designated for downlink transmission. option 3: The part of the special subframe designated for bidirectional transmission. option 4: The part of the special subframe designated for multicast transmission. option 5: The part of the special subframe designated for unicast transmission. 