Question: What action is a UE required to take when it is attached for emergency bearer services?
Option 1: Perform periodic tracking area updating
Option 2: Initiate normal and combined tracking area updating
Option 3: Respond to paging messages without any conditions
Option 4: Perform the eCall inactivity procedure at expiry of timer T3444 or T3445
Explanation: According to the provided text, when a UE is attached for emergency bearer services, it is exempt from performing periodic tracking area updating. This implies that the UE will not perform this action under these specific circumstances.