Question: When does a UE use Type 2A SL channel access procedures for transmitting only S-SSB (Synchronization Signal and System Broadcast) in a shared spectrum channel?
Option 1: If the time duration of S-SSB transmission exceeds a duty cycle of at most 50% with no gap between transmissions.
Option 2: When resuming SL transmission after a brief pause, without continuous sensing of the channel's idleness.
Option 3: If the time duration of S-SSB transmission(s) is at most with a duty cycle of at most (as specified for Type 2A procedures).
Option 4: Following another UE's SL transmission in a shared channel occupancy, regardless of the S-SSB transmission duration.
Explanation: According to specifications for Type 2 SL channel access procedures, specifically for Type 2A, a UE uses these procedures when transmitting only S-SSB with a time duration adhering to a duty cycle of at most (as specified). This ensures controlled and efficient use of shared spectrum resources. Option 3 correctly captures this condition without misinterpreting or adding unrelated criteria.