What type of train includes multiple-unit passenger cars of various M-Series?

Answer: B — M-Series Equipment

The classification of multiple-unit passenger cars specifically as M-Series Equipment is accurate because M-Series refers to a line of modern commuter rail passenger coaches designed for use in multiple-unit configurations. This type of train can operate without a traditional locomotive, as each unit has its own propulsion system and can couple with others to form longer trains. In contrast, a Deadhead Train typically refers to a train movement where crew members reposition themselves or equipment without passengers. An Engine is a standalone locomotive that might pull or push train cars but in this context doesn't capture the multiple-unit structure inherent to the M-Series. Lastly, a Light Engine describes a locomotive that operates without any attached train cars, focusing solely on moving the engine itself without passengers. Ultimately, M-Series Equipment is the precise term that encompasses the multiple-unit passenger cars in question, making it the correct choice.