Comprehensive and Detailed Explanation From Exact Extract:

PXE (Preboot Execution Environment) allows workstations to boot over the network and download an OS image from a server. It is ideal for automating mass deployments using baseline images across many machines without the need for physical media.

A. An ISO is a disk image file but requires mounting or physical media.

B. Secure Boot is a security feature, not a method of deploying OS images.

C. USB requires manual installation and is not suitable for automated deployment at scale.