What best describes the primary role of mortar units?

The primary role of mortar units is to provide both lethal and non-lethal indirect fires to support ground troops. Mortars are versatile weapons capable of delivering high-explosive projectiles to engage enemy positions, suppress threats, and provide close support for infantry operations. This capability allows combat units to maintain flexibility and adapt to various combat scenarios, including direct enemy engagement and area suppression.

Non-lethal indirect fire can include the use of illumination rounds or smoke rounds, which serve to enhance visibility on the battlefield or obscure troop movements, respectively. This dual capability ensures that mortar units can effectively support the overall mission objectives while also protecting their own forces and managing the battlefield environment.

Other options, while related to aspects of military operations, do not encompass the full scope of mortar units' capabilities, which include both lethal and non-lethal functions.