A $2\mathrm{.}0-$N rock slides on a frictionless inclined plane.Which one of the following statements is true concerning the normal force that the plane exerts on the rock?The normal force is less than $2\mathrm{.}0$ N$,$ but greater than zero newtons.The normal force is greater than $2\mathrm{.}0$ N$.$The normal force is zero newtons.The normal force is $2\mathrm{.}0$ N$.$It increases as the angle of inclination, $0,$ is increased.