# An edge of a variable cube is increasing at the rate of $3\; cm/s$. How fast is the volume of the cube increasing when the edge is $10\; cm$ long?
$\begin{array}{1 1} (A)\;900cm^3/s \\ (B)\;500cm^3/s \\ (C)\;600cm^3/s \\(D)\;100cm^3/s \end{array}$