Answer:
Option b)
Explanation:
Radio telescopes are a lot bigger than optical telescopes since radio wavelengths are any longer than optical wavelengths.
The more extended wavelengths implies that the radio waves have lower energy than optical light waves.
So as to gather enough radio photons to identify a sign, the radio dishes must be exceptionally huge.
Radio telescopes uses a large reflecting dish.
Radio telescope like any other telescope makes use of a lenses' system.
Since visible light can be easily seen from the space thus radio telescope are used for astronomical purpose to capture the light from other EM spectrum like the radio range.
