答案：A
$\begin{array}{rcl}
f(-1) & = & 8 \\
(-1)^2 -9(-1) + c & = & 8 \\
10 + c & = & 8 \\
c & = & -2
\end{array}$
$\begin{array}{rcl}
f(-1) & = & 8 \\
(-1)^2 -9(-1) + c & = & 8 \\
10 + c & = & 8 \\
c & = & -2
\end{array}$
Resources for HKDSE Mathematics
