Which one is an application package?

An application package typically refers to a software package or program that can be installed and run on a computer. Among the options you provided:

A) DOS (Disk Operating System) - This is not an application package but rather an operating system.

B) LOTUS - Lotus Software (called Lotus Development Corporation before its acquisition by IBM) was an American software company based in Massachusetts. Lotus is most commonly known for the Lotus 1-2-3 spreadsheet application, the first feature-heavy, user-friendly, reliable and WYSIWYG-enabled product to become widely available in the early days of the IBM PC, when there was no graphical user interface.

C) LINUX - Linux is not an application package but an operating system similar to Ubuntu.

D) UBUNTU - Ubuntu is an operating system, not an application package.