不等式 $\frac{7}{2 x-1}>1$ 的解集为
A. $\left\{x \left\lvert\, \frac{1}{2} < x < 4\right.\right\}$
B. $\left\{x \left\lvert\, \frac{1}{4} < x < 2\right.\right\}$
C. $\left\{x \left\lvert\, x < \frac{1}{2}\right.\right.$ 或 $\left.x>4\right\}$
D. $\left\{x \left\lvert\, x < \frac{1}{4}\right.\right.$ 或 $\left.x>2\right\}$