A train starts from rest and accelerates uniformly until it has traveled $2\mathrm{.}1$ km and acquired a forward velocity of $24$ m$/$s$.$ The train then moves at a constant velocity of $24$ m$/$s$$for $400$ s$.$ The train then slows down uniformly at $0\mathrm{.}065$ m$/$s$2,$until it is brought to a halt. The distance traveled by the train while slowing down is closest to:

$4\mathrm{.}4$ km$.$

$4\mathrm{.}2$ km$.$

$4\mathrm{.}0$ km$.$

$3\mathrm{.}8$ km$.$