Question: What parameters are used to form the input S to the Key Derivation Function (KDF) when deriving a UPU-MAC-IAUSF from KAUSF?
Option 1: FC = 0x7A, P0 = UE Parameters Update Data (starting from octet 1), L0 = length of UE Parameters Update Data, P1 = CounterUPU, L1 = length of CounterUPU
Option 2: FC = 0x7B, P0 = UE Parameters Update Data (starting from octet 1), L0 = length of UE Parameters Update Data, P1 = CounterUPU, L1 = length of CounterUPU
Option 3: FC = 0x7B, P0 = UE Parameters Update Data (starting from octet 23), L0 = length of UE Parameters Update Data, P1 = CounterUPU, L1 = length of CounterUPU
Option 4: FC = 0x7C, P0 = UE Parameters Update Data (starting from octet 23), L0 = length of UE Parameters Update Data, P1 = CounterUPU, L1 = length of CounterUPU
Explanation: The correct parameters used to form the input S to the KDF when deriving a UPU-MAC-IAUSF from KAUSF are FC = 0x7B, P0 = UE Parameters Update Data (starting from octet 23), L0 = length of UE Parameters Update Data, P1 = CounterUPU, and L1 = length of CounterUPU.