C

Young's modulus is defined as the ratio of stress (force per unit area) to strain (deformation relative to original length). The unit of stress is Pascals (Pa), which is equivalent to N/m². Therefore, the unit of Young's modulus can be expressed as:
Young's Modulus (E) = \frac{Stress}{Strain} = \frac{N/m^2}{dimensionless} = N/m^2
So, the unit of Young's modulus is also expressed as Nm (Newton per meter), which is not commonly used; however, it simplifies back to Pasials (Pa). The correct representation here is given by option Nm.