An open glass tube is immersed in mercury in such a way that a length of $8\; cm$ extends above the mercury level. The open end of the tube is then closed and sealed and the tube is raised vertically up by additional $46\; cm$. What will be length of the air column above mercury in the tube now? (Atmospheric pressure = $76\; cm$ of Hg)

Question

$\begin{array}{1 1}(A)\;38\;cm \\ (B)\;6\;cm \\(C)\;16\;cm \\(D)\;22\;cm \end{array}$