The number of bacteria in a petri dish increases by 18% every hour. If there were initially 200 bacteria placed in the petri dish, which function can be used to determine the number of bacteria in the petri dish in exactly x hours?A: y=200(1.18)^xB: y=200(1.82)^xC: y=200(0.82)^xD: y=200(0.18)^x