Question: In the context of Generic Authentication Architecture (GAA) and Generic Bootstrapping Architecture (GBA), what is the primary purpose of the `Nudm_UEAuthentication_GetGbaAv` service operation initiated by the Bootstrapping Server Function (BSF)?
Option 1: To fetch and provide GBA authentication vectors to facilitate UE authentication based on the provided SUPI.
Option 2: To manage UE's secure connection setup.
Option 3: To handle UE registration and deregistration from the network.
Option 4: To convert IMSI-based IMPI to SUPI for UE identification.
Explanation: The primary purpose of `Nudm_UEAuthentication_GetGbaAv` is to fetch GBA authentication vectors using the provided SUPI, facilitating secure UE authentication. This aligns with GAA and GBA's focus on generic authentication and bootstrapping for secure network access.