SPRING, Texas (KTRK) -- Klein Oak High School administrators are investigating after a student was allegedly selling brownies that may have been laced with an unknown substance.One Klein Oak mom tells ABC13 that she believes the brownies were laced with marijuana.The student was reportedly selling the brownies before classes began Friday morning.The two Klein Oak students that ate the brownies have been taken to the hospital. All parents of known involved students have been notified.The investigation is ongoing.