Final answer:
All of the given factors contribute to the resolution attainable by a microscope.
Step-by-step explanation:
The correct option is E: all of these contribute to resolution. All of the given factors contribute to the resolution attainable by a microscope. The wavelength of light affects resolution because shorter wavelengths can resolve smaller objects. The magnification of the objective lens enhances our ability to see details of small objects. The refractive index of the material between the specimen and the lens affects the bending of light, which can impact resolution. The numerical aperture of the lens determines its ability to gather light, which is important for achieving higher resolution.