Question: What is the primary purpose of the cipher algorithm agreement feature in the context of confidentiality on the network access link?
Option 1: To ensure that user data cannot be overheard on the radio access interface.
Option 2: To securely negotiate the algorithm used for subsequent communication between the MS and the SN.
Option 3: To agree on a cipher key that can be used subsequently by the MS and the SN.
Option 4: To authenticate the identity of the MS and the SN.
Explanation: The correct answer is Option 2 because the primary purpose of the cipher algorithm agreement feature is to securely negotiate the algorithm used for subsequent communication between the Mobile Station (MS) and the Serving Network (SN). This ensures that both parties agree on a common encryption algorithm, which is essential for maintaining confidentiality on the network access link.