Answer is: B) The cart will move to the left.
A newton (N) is the International unit of measure for force.
One newton is the force needed to accelerate one kilogram of mass at the rate of one metre per second squared in direction of the applied force.
The cart will move to the left by the force of 2 newton.
F(cart) = 7 N - 5 N.
F(cart) = 2 N to the left.