Below is the graph of the derivative $f'(x)$ of a function defined on the interval (0,8). You can click on the graph to see a larger version in a separate window.

Refer to the graph to answer each of the following questions. For part (A), use interval notation to report your answer. (If needed, you use U for the union symbol.)

(A) For what values of $x$ in (0,8) is $f(x)$ concave down? (If the function is not concave down anywhere, enter "{}" without the quotation marks.)

(B) Find all values of $x$ in (0,8) is where $f(x)$ has an inflection point, and list them (separated by commas) in the box below. (If there are no inflection points, enter -1000.)