Final answer:
The security software designed for mainframe systems is RACF (Resource Access Control Facility), which controls access, manages identities, and facilitates auditing on mainframe systems.
Step-by-step explanation:
The software product that provides basic security for a mainframe system is RACF (Resource Access Control Facility). RACF, developed by IBM, is a security server that provides access control and auditing functionality for the z/OS and z/VM mainframe operating systems. It enables an administrator to define and enforce access policies and ensures unauthorized users are prevented from accessing sensitive information. RACF manages identities, enforces access controls, supports auditing, and provides reporting capabilities.
Other options provided in the question do not specifically provide security for mainframe systems. LDAP (Lightweight Directory Access Protocol) is a protocol for accessing and maintaining distributed directory information services. PKI (Public Key Infrastructure) involves systems that manage keys and certificates for encrypting data and securing communications. SAF (Security Authorization Facility) is a generalized interface that can work with various security products, including RACF, but on its own, it is not a specific product providing security.