已知\(\{a_{n}\}\)是首项为\(1\)的等比数列，\(S_{n}\)是\(\{a_{n}\}\)的前\(n\)项和，且\(9S_{3}=S_{6}\)，则数列\(\left\{ \left. \dfrac{1}{a_{n}} \right. \right\}\)的前\(5\)项和为\((\) \()\)
A. \( \dfrac{15}{8}\)或\(5\)
B. \( \dfrac{31}{16}\)或\(5\) C. \( \dfrac{31}{16}\) D. \( \dfrac{15}{8}\)
