Question: What triggers a UE (User Equipment) to limit the usage of transport format combinations for an assigned transport format set?
Option 1: Estimation that a certain TFC (Transport Format Combination) and E-TFC (Enhanced Transport Format Combination) would require more power than the maximum transmit power.
Option 2: Receipt of a specific command from the network operator to reduce power consumption.
Option 3: Detection of poor channel quality indicators from the base station.
Option 4: Expiration of a timer set for transmission power management.
Explanation: This is correct because, as per specifications, when a UE estimates that using certain TFC and E-TFC settings would exceed its maximum transmit power, it must limit these combinations to ensure network coverage maximization.