For the function below, find a) the critical numbers; b) the open intervals where the function is increasing, and c) the open intervals where it is decreasing 1(x)=x+3 GILD a) Find the critical number(s). Select the correct choice below and, if necessary, fill in the answer box to complete your choice OA. The critical number(s) is/are (Type an integer or a simplified fraction. Use a comma to separate answers as needed.) OB. There are no cntical numbers b) Determine the interval(s) on which the function is increasing Select the correct choice below and, if necessary, fill in the answer box to complete your choice OA. The function is increasing on (Type your answer in interval notation. Simplify your answer. Use integers or fractions for any numbers in the expression. Use a comma to separate answers as needed) B. The function is never increasing c) Determine the interval(s) on which the function is decreasing Select the correct choice below and, if necessary, fill in the answer box to complete your choice OA. The function is decreasing on (Type your answer in interval notation. Simplify your answer. Use integers or fractions for any numbers in the expression Use a comma to separate answers as needed) OB. The function is never decreasing