已知抛物线\(C\)：\(y ^{2} =2px(p > 0)\)的焦点为\(F\)，过点\(F\)的直线\(l\)与抛物线\(C\)交于点\(A\)，\(B\)两点，且直线\(l\)与圆\(x ^{2} -px+y ^{2} - \dfrac {3}{4}p^{2} =0\)交于\(C\)，\(D\)两点，若\(|AB|=2|CD|\)，则直线\(l\)的斜率为\((\:\:\:\:)\)
A. \(± \dfrac { \sqrt {2}}{2}\)
B. \(± \dfrac { \sqrt {3}}{2}\) C. \(±1\) D. \(± \sqrt {2}\)
