A body of mass $2 \mathrm{~kg}$ travels according to law $x(t)=p t+q t^{2}+r t^{3}$, where $p=3 \mathrm{~ms}^{-1}, q=4 \mathrm{~ms}^{-1}$ and
$r=5 \mathrm{~ms}^{-3}$. The force acting on the body at $t=2 \mathrm{~s}$ is [NCFRT Exemplat]
(a) $136 \mathrm{~N}$
(b) $134 \mathrm{~N}$
(c) $158 \mathrm{~N}$
(d) $68 \mathrm{~N}$