Which of the following software can't be categorized as an application software?

Application software carries out specific end-user tasks such as writing documents, managing databases, or performing calculations. A database management program (DBM/DBMS), a spreadsheet, and a word processor all fit this description, since each one lets a user directly produce or manage their own content.

MS-DOS is different. It is an operating system, a form of system software whose job is to manage the computer's hardware, memory, and files and to provide the platform on which application programs like spreadsheets and word processors run. Because it manages the machine itself rather than performing a user task, it cannot be classified as application software.

Exam takeaway: before classifying software, ask whether it manages the computer (system software, including operating systems like MS-DOS) or whether it lets the user create and manipulate their own content (application software).