Which gun system is included on the TICONDEROGA class cruisers?

The correct choice encompasses the weapon systems commonly found on TICONDEROGA class cruisers. Specifically, the Mk-38 25mm machine gun is a part of their armament, designed for anti-aircraft and close-in defense capabilities. These vessels are equipped to operate in complex maritime environments and need systems that can effectively counter small craft and aerial threats.

The Mk-38 25mm machine gun is often mounted to enhance close-range protective capabilities, supporting overall mission objectives. This system, along with others on the cruiser, contributes to the ship’s versatility in various combat scenarios.

In terms of the other options, while the Vulcan Phalanx is a vital close-in weapon system for protecting ships from missile threats, it is not the Mk-38. The 75mm cannon and the Dart missile launcher do not form part of the TICONDEROGA class cruiser’s standard armament, indicating that the Mk-38 is the accurate selection here based on the cruiser's operational design and intended defense capabilities.