Question: In a 3GPP system, what is the primary condition for transferring User Identity (UE: User Equipment) information to a service provider?
Option 1: The user has explicitly consented to share this information during service registration, and it is necessary for the service provision.
Option 2: The service provider requests it, regardless of the user's consent or the necessity for service provision.
Option 3: The type of User Identity information is categorized as 'public' within the 3GPP system.
Option 4: The transfer occurs anonymously, without revealing identifiable User Equipment information.
Explanation: This answer aligns with privacy requirements, emphasizing user consent (obtained during service registration) and necessity for service provision are paramount to protect user privacy while facilitating service delivery.