Question: In UTRAN, what is the primary purpose of the 'MBMS Preferred Frequency Layer Information' IE in RNSAP signalling?
Option 1: To indicate the minimum required bandwidth for a CELL_DCH UE to access an MBMS Bearer Service.
Option 2: To signal the preferred frequency layer for MBMS transmission in cells hosting at least one CELL_FACH UE with the same SRNC as the CRNC.
Option 3: To notify the SRNC about the current load of MBMS Bearer Services in neighboring cells under a different CRNC.
Option 4: To specify the preferred frequency layer for an MBMS Bearer Service (identified by TMGI) in cells with at least one CELL_DCH UE, where the SRNC differs from the CRNC.
Explanation: This IE's purpose is to specify a preferred frequency layer for an MBMS Bearer Service in specific conditions (CELL_DCH UEs with differing SRNC and CRNC). The other options misrepresent the IE's purpose or describe irrelevant scenarios.