9. Let $S _ { n }$ denote the sum of the first $n$ terms of an arithmetic sequence $\left\{ a _ { n } \right\}$. Given $S _ { 4 } = 0 , a _ { 5 } = 5$, then\\
A. $a _ { n } = 2 n - 5$\\
B. $a _ { n } = 3 n - 10$\\
C. $S _ { n } = 2 n ^ { 2 } - 8 n$\\
D. $S _ { n } = \frac { 1 } { 2 } n ^ { 2 } - 2 n$
\section*{Mathematics (Science) Test Paper Page 2 (Total 5 Pages)}