定义在\(R\)上的奇函数\(f(x)\)，满足\(f(\dfrac{1}{2})=0\)，且在\((0,+\infty )\)上单调递减，则\(xf(x) > 0\)的解集为\((\) \()\)
A. \(\{x|x < - \dfrac{1}{2} \)或\(x > \dfrac{1}{2} \}\)
B. \(\{x|0 < x < \)\( \dfrac{1}{2} \)或\(- \dfrac{1}{2} < x < 0\}\) C. \(\{x|0 < x < \)\( \dfrac{1}{2} \)或\(x > - \dfrac{1}{2} \}\) D. \(\{x|-\)\( \dfrac{1}{2} \)\( < x < 0\)或\(x > \dfrac{1}{2} \}\)
