Question: What is a mandatory attribute in the subject name of an RN (Radio Network) certificate, used in the TLS handshake between RN and UICC (Universal Integrated Circuit Card), to support generating a unique identity for an RN?
Option 1: organizationName (O)
Option 2: organizationalUnitName (OU)
Option 3: localityName (L)
Option 4: Both countryName (C) and serialNumber attributes
Explanation: The correct answer is Option 4 because, according to the RN certificate profile specifications, the support of both the countryName (C) and serialNumber attributes in the subject name is mandatory. This requirement is specifically designed to assist operators in creating a unique identity for each Radio Network (RN), highlighting the importance of these attributes in ensuring uniqueness and security within the network.