Find the largest open intervals on which the function is concave upward or concave downward, and find the location of any points of inflection. f(x) = - 4x + 2x + 2 . . . Select the correct choice below and fill in the answer box(es) to complete your choice. (Type your answer in interval notation. Use a comma to separate answers as needed. integers or fractions for any numbers in the expression.) O A. The function is concave downward on The function never has an interval th concave upward/downward. O B. The function is concave upward on The function never has an interval that is concave upward/downward. O C. The function is concave upward on and concave downward on