# Viruses cannot be cultured in any artificial medium because they

$\begin{array}{1 1}(A)\;\text{Lack DNA}\\(B)\;\text{Have no RNA}\\(C)\;\text{Are nonliving}\\(D)\;\text{Lack metabolic machinery}\end{array}$

Viruses cannot be cultured in any artificial medium because they lack metabolic machinery
Hence (D) is the correct answer.