Which one of the following is not an application software?

A Linker is not an application software; it is a system software (utility program) that takes one or more object files generated by a compiler and combines them into a single executable program. Spreadsheet (like MS Excel), AutoCAD, and MS PowerPoint are all application software designed for end-users to perform specific tasks such as data analysis, computer-aided design, and presentations respectively. Hence, Linker is the correct answer.