For an optical fiber consists of a core (refractive index =\[{{\mu }_{1}}\]) and cladding (refractive index =\[{{\mu }_{2}}\])

• A. \[{{\mu }_{1}}>{{\mu }_{2}}\]
• B. \[{{\mu }_{1}}<{{\mu }_{2}}\]
• C. \[{{\mu }_{1}}={{\mu }_{2}}\]
• D. \[\frac{{{\mu }_{1}}}{{{\mu }_{2}}}=\frac{1}{2}\]