The correct answer is C. Suitable choice of core and cladding components.
Intrinsic absorption is the absorption of light by the material itself, and it is a major limitation in the performance of optical fibers. It can be minimized by choosing materials with low absorption coefficients, and by designing the fiber so that the light is guided away from the core-cladding interface, where absorption is highest.
Ionization is the process of removing an electron from an atom or molecule, and it can also lead to absorption of light. However, ionization is not a major factor in intrinsic absorption in optical fibers, because the energy required to ionize most materials is much higher than the energy of visible light.
Radiation is the emission of energy in the form of waves or particles, and it can also lead to absorption of light. However, radiation is not a major factor in intrinsic absorption in optical fibers, because the energy of most forms of radiation is much higher than the energy of visible light.
Melting is the process of converting a solid into a liquid, and it does not affect the absorption of light. Therefore, option D is also incorrect.