A mass $m$ is supported by a massless string wound around a uniform hollow cylinder of mass $m$ and radius $R$. If the string does not slip on the cylinder, with what acceleration will the mass fall on release?

Question

$\begin{array}{1 1}(A)\;\frac{5g}{6}\\ (B)\;g \\(C)\;\frac{2g}{3} \\(D)\;\frac{g}{2} \end{array} $