(a) Except as otherwise provided in subsection (b) of this Code section, a person who knowingly and willfully obstructs or hinders any law enforcement officer in the lawful discharge of his official duties is guilty of a misdemeanor.

(b) Whoever knowingly and willfully resists, obstructs, or opposes any law enforcement officer, prison guard, correctional officer, probation supervisor, parole supervisor, or conservation ranger in the lawful discharge of his official duties by offering or doing violence to the person of such officer or legally authorized person is guilty of a felony and shall, upon conviction thereof, be punished by imprisonment for not less than one nor more than five years.