i need help solving this problem

Find the open intervals where the function f(x) = -28 + 6x + 166x - 7 is concave upward or concave downward. Find any inflection points, Select the correct choice below and, if necessary, fill in the answer box to complete your choice A. The function has a point of infection at (Type an ordered pair using integers or fractions. Simplify your answer. Use a comma to separate answers as needed.) B. The function does not have an inflection point Select the correct choice below and. If necessary, fill in the answer box to complete your choice. O A The function is concave upward on the interval(s) (Type your answer in interval notation. Une intogers of fractions for any numbers in the expression Simplify your answer. Use a comma to soporom O B. The function is never concave upward. Select the correct choice below and, if necessary, fill in the answer box to complete your choice O A. The function is concave downward on the interval(s) (Type your answer in interval notation. Use Integers or fractions for any numbers in the expression Simplify your answer. Use a comma to separate B. The function is never concave downward