A $4\mathrm{.}0$ kg block on a smooth horizontal surface is acted upon by two forces: a horizontal force of $70$ N acting to the right and a horizontal force of $30$ N to the left. The acceleration of the block will be

$2\mathrm{.}3\frac{m}{s^2}$ to the right

$4\mathrm{.}0\frac{m}{s^2}$ to the right

$10\mathrm{.}0\frac{m}{s^2}$ to the right

$21\mathrm{.}0\frac{m}{s^2}$ to the right