Question: What is the maximum number of HARQ-ACK codebooks that can be constructed simultaneously by a UE, corresponding to different priorities?
Option 1: One
Option 2: Two
Option 3: Three
Option 4: Four
Explanation: According to the specifications, up to two HARQ-ACK codebooks corresponding to a priority (high/low) can be constructed simultaneously by a UE. This allows for efficient transmission of HARQ-ACK information over the air interface.