Which of the Following Pairs Forms a Fundamental Set of Solutions

Multiple Choice

Which of the following pairs forms a fundamental set of solutions of the Cauchy Euler differential equation .

A) $\left\{x^{-5}, x^{-5} \cos (\ln x) \right\}$
B) $\left\{x^{5}, x^{-5}\right\}$
C) $\left\{x^{5}, x^{5} \ln x\right\}$
D) $\left\{x^{-5}, x^{-5} \ln x\right\}$
E) $\left\{x^{5}, x^{5} \cos (\ln x) \right\}$