For Suitable Power Confinement of Fundamental Mode, the Normalized Frequency

For suitable power confinement of fundamental mode, the normalized frequency v should be maintained in the range 1.5 to 2.4?m and the fractional index difference must be linearly increased as a square function while the core diameter is linearly reduced to keep v constant. This confinement is achieved by-

A) increasing level of silica doping in fiber core
B) increasing level of germanium doping in fiber core
C) decreasing level of silica germanium in fiber core
D) decreasing level of silica doping in fiber core