D.) Because it has a definite composition...
Answer:
Because it radiates a spectre of frequencies, this means that it radiates in a continuous range of frequencies, ones with more intensity (like x-ray and ultraviolet) and others with less intensity (like the visible light). While most of the radiation is not in the visible range, there still is a part of the radiation in the visible spectre. And while this part is not the most intense part, the radiation is so large that we can see a very bright visible light.
I'm not really sure if it's completely right but I was taught that light can travel without a medium because light is composed of quanta called photons, and since it is a property of photons that they don't require a medium of transmission
( sorry if that doesn't make sense )
Plz feel free to adk more if u hv any confusion!!!
A) it has a net force because we know that it’s going down in a direction, so there is no force being cancelled out.