二元一次方程x﹣2y=1有无数个解，下列4组值中不是该方程解的是（　　）

A：$\left\{\begin{array}{c}x=2\\ y=3\end{array}\right.$

B：$\left\{\begin{array}{c}x=-1\\ y=-1\end{array}\right.$

C：$\left\{\begin{array}{c}x=1\\ y=0\end{array}\right.$

D：$\left\{\begin{array}{c}x=0\\ y=-\frac{1}{2}\end{array}\right.$