Question: What is the primary purpose of the `rf-RetuningTimeUL-r14` field in E-UTRA UE radio access capabilities?
Option 1: To indicate the time required for a UE to switch from idle to active state on a PUSCH-less SCell.
Option 2: To specify the maximum allowed delay for UL transmission buffering during RF retuning on the same frequency band.
Option 3: To inform the network about the interruption time on UL transmission when a UE performs RF retuning to switch between band pairs for transmitting SRS on a PUSCH-less SCell.
Option 4: To define the minimum time interval between two consecutive SRS transmissions on different SCells.
Explanation: The `rf-RetuningTimeUL-r14` field indicates the UL transmission interruption time during RF retuning for band pair switching, specifically for transmitting SRS on a PUSCH-less Secondary Cell (SCell), crucial for network planning and resource allocation to minimize service interruptions.