| $x$ | $-2$ | 0 | 3 | 5 | 6 |
| $f ^ { \prime } ( x )$ | 3 | 1 | 4 | 7 | 5 |
Let $f$ be a polynomial function with values of $f ^ { \prime } ( x )$ at selected values of $x$ given in the table above.
\begin{center}
\begin{tabular}{ | c | | r | r | r | r | r | }
\hline
$x$ & $-2$ & 0 & 3 & 5 & 6 \\
\hline
$f ^ { \prime } ( x )$ & 3 & 1 & 4 & 7 & 5 \\
\hline
\end{tabular}
\end{center}
Which of the following must be true for $-2 < x < 6$ ?
(A) The graph of $f$ is concave up.
(B) The graph of $f$ has at least two points of inflection.
(C) $f$ is increasing.
(D) $f$ has no critical points.
(E) $f$ has at least two relative extrema.