The density increases.
When gases are compressed, their volume decreases, and the resulting pressure increases. The temperature will change if either P or V are held constant. Since the volume decreases, then density, or m/V, increases.
P×V ~ T
The most common value for the speed of light is 3*10^8 meters/second.
A more accurate number is <span>299 792 458 m/second, but that number is hardly ever used.</span>
The answer is a tell me if I am wrong.
I would chose as the answer A I think that it uses so in the correctly.