All other options are true except option (c). As we know red light is least scattered in the atmosphere while blue light is more scattered.
Scattering of light takes places when light waves pass through some material medium which has some particles of considerable size, then the light rays get deflected from a straight path and scattered into all directions. This happens because light is absorbed by the particles in the form of energy.
Dispersion of light takes place as various colours of white light travel with different speeds in air.