Which of the following describes when a user installs an unauthorized application by bypassing the...

The best answer is B. Sideloading.

Sideloading is the installation of an application from outside the official or authorized application store, often by directly installing a binary package or application file. This bypasses standard review and distribution controls.

Why the other options are incorrect:

A. JailbreakingJailbreaking removes or bypasses manufacturer or operating system restrictions, often on mobile devices. It may enable sideloading, but it is not the same thing as the act described.

C. Memory injectionMemory injection is a technique used to place code into another process’s memory. It is unrelated to installing an app from an unauthorized source.

D. VM escapingVM escape is an attack in which code breaks out of a virtual machine into the host environment. It does not describe unauthorized app installation.

From a Security+ standpoint, bypassing the approved app store and directly installing a binary is the definition of sideloading.