In mechanics of materials, the bending stress of a beam in bending can be determined by the equation σ = MyIwhere expressed in terms of SI base units M is the bending moment in Newton-meters (N-m), y is the distance from the neutral axis in meters (m), and I is the moment of inertia in meters to the fourth power (m4). The bending stress σ has the same units as those of:_____.a) pressure.b) density.c) force.d) spring constant.