2. Given the inequality $\left(a^{2}-3\right) x^{2}+5 x-2>0$ has the solution set $\left(\frac{1}{2}, 2\right), a$ equals $(\quad)$.
A. 1
B. -1
C. $\pm 1$
D. 0
2. C. From $\frac{-2}{a^{2}-3}=\frac{1}{2} \cdot 2$ we get $a= \pm 1$, which, upon verification, satisfies the problem's conditions.