A beam of polychromatic light passes through a thin prism of prism angle \(6^\circ\). The refractive index of the material of the prism varies with wavelength \((\lambda)\) as \(n(\lambda) = \alpha \lambda + \dfrac{\beta}{\lambda^{2}}\) where \(\alpha = 3 \, \mu \text{m}^{-1}\) and \(\beta = 0.096 \, \mu \text{m}^{2}\). If \(\lambda_{\min}\) is the wavelength at which the angle of minimum deviation \(D_{m}\) is smallest, then the correct value of \(D_{m}\) at \(\lambda_{\min}\) is:
