Explanation:

UNIX, MS-DOS, and WINDOWS 98 are all operating systems (OS). An operating system is fundamental software that manages computer hardware and software resources, providing common services for computer programs. It's the core software that allows other applications to run. ACCESS (Microsoft Access) is a database management system (DBMS) application software, not an operating system. It is a specific application that runs *on* an operating system (like Windows). Therefore, ACCESS is the 'odd man out' as it belongs to a different category of software (application software) compared to the other options, which are all operating systems.