2. Given the general term formula of the sequence $\left\{a_{n}\right\}$ as $a_{n}=\frac{2 n-17}{2 n-19}(n=1,2, \cdots)$, then the largest term in $\left\{a_{n}\right\}$ is
A. $a_{1}$
B. $a_{9}$
C. $a_{10}$
D. $a_{12}$
$a_{n}=\frac{2 n-17}{2 n-19}=1+\frac{2}{2 n-19} \Rightarrow a_{9}=-1, a_{10}=3$, so the answer is $C$.