(a) A school bus driver found to have used an illegal drug shall be terminated from his or her employment.

(b) A school bus driver found to have any measurable alcohol in his or her system during the school day shall be subject to disciplinary action at the discretion of the local board of education.

(c) A school bus driver who refuses to provide body fluid, when requested to do so in accordance with drug testing or random alcohol testing conducted pursuant to this part and rules and regulations promulgated under this part, shall be terminated from employment.