A $910-kg$ object is released from rest at an altitude of $1200$ km above the north pole of the earth. If we ignore atmospheric friction, with what speed does the object strike the surface of the earth? $o{\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}G=6\mathrm{.}67{10}^{-11}\frac{(N)*m^2}{k{g}^2},M_{\text{e}\text{a}\text{r}\text{t}\text{h}}=5\mathrm{.}97{10}^{24}kg,$ the polar radius of the earth is $6357$ km $)$

$4\mathrm{.}5k\frac{m}{s}$

$2\mathrm{.}7k\frac{m}{s}$

$4\mathrm{.}8k\frac{m}{s}$

$2\mathrm{.}2k\frac{m}{s}$

$3\mathrm{.}2k\frac{m}{s}$