A planet having mass $9M_e$ and radius $4R_e$, where $M_e$ and $R_e$ are mass and radius of earth respectively, has escape velocity in km s$^{-1}$ given by: (Given escape velocity on earth $V_e = 11.2 \times 10^3$ m s$^{-1}$)\\
(1) 67.2\\
(2) 16.8\\
(3) 11.2\\
(4) 33.6