Which statement is true regarding the Mk19 general characteristics?

The statement that the Mk19 is air-cooled and fully automatic is accurate due to its design and operational characteristics. The Mk19 is a belt-fed grenade launcher that operates through a blowback mechanism, allowing it to achieve a high rate of fire. As an air-cooled system, it relies on ambient air to dissipate heat generated during sustained firing rather than needing an external cooling system, which is essential for maintaining performance in combat scenarios. The fully automatic capability of the Mk19 enables continuous fire as long as the trigger is held down, allowing for a sustained barrage of grenades, which can enhance its effectiveness in various tactical situations. This feature is particularly important for providing suppressive fire to support infantry operations.