How many modes possible with a multimode step-index with a core diameter of 50 um, a core refractive index of 1.6, a cladding refractive index of 1.584, and a wavelength of 1300 nm.
∙ A. 456
∙ B. 213
∙ C. 145
∙ D. 372
∙ A. 456
∙ B. 213
∙ C. 145
∙ D. 372