Question: What are the two options for Sidelink HARQ feedback using PSFCH?
Option 1: One option uses PSFCH to transmit ACK or NACK on a shared resource, while the other option uses PSFCH to transmit only NACK on a dedicated resource.
Option 2: One option uses PSFCH to transmit either ACK or NACK using a resource dedicated to a single PSFCH transmitting UE, while the other option uses PSFCH to transmit NACK, or no PSFCH signal is transmitted, on a resource that can be shared by multiple PSFCH transmitting UEs.
Option 3: One option uses PSFCH to transmit ACK only on a dedicated resource, while the other option uses PSFCH to transmit NACK only on a shared resource.
Option 4: One option uses PSFCH to transmit no signal on a dedicated resource, while the other option uses PSFCH to transmit either ACK or NACK on a shared resource.
Explanation: The correct answer is Option 2 because it accurately describes the two options for Sidelink HARQ feedback using PSFCH as mentioned in the text. In one option, PSFCH transmits either ACK or NACK using a dedicated resource, while in the other option, PSFCH transmits NACK or no signal on a shared resource.