A drug that stimulates reproduction is introduced into a colony of bacteria After t minutes the number of bacteria is given approximately by the following equation Use the equation to answer parts A through D N t 1000 27t t 0 t 18 A When is the rate of growth N t increasing Select the correct choice below and if necessary fill in the answer box to complete your choice OA The rate of growth is increasing on Type your answer in interval notation Use a comma to separate answer as needed OB The rate of growth is never increasing