(1) "Use a firearm" means to discharge a firearm.
(2) "Serious bodily injury" means a physical condition which creates a substantial risk of death, serious personal disfigurement, or protracted loss or impairment of the function of a bodily member or organ.
(B) It is unlawful for a person who is under the influence of alcohol or a controlled substance to use a firearm in this State.
(C) A person who violates the provisions of subsection (B) is guilty of a misdemeanor and, upon conviction, must be fined not less than two thousand dollars or imprisoned not more than two years.
(D) This article does not apply to persons lawfully defending themselves or their property.