Answer is: A. A force is being applied to the mass.
Newton's second law of motion: F = m · a.
F - force applied.
m - mass of the object receiving the force.
a - the acceleration of the object.
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 weight of an object is the amount of force acting on the object due to gravity. SI unit for weight is newton (N).
