Astronomy can best be described as a/an
a. daily horoscope.
b. study of objects pertaining to the interior part of the earth.
c. study of objects beyond the earth's atmosphere.
d. air force pilot on a naval carrier.

C.,  cause stars aren't located in earth's atmosphere or " the interior part of Earth" and daily horoscope is a more astrology thing, and Air Force pilot on a Naval carrier? Come on now.

C. study of objects beyond the Earth's atmosphere. Astronomy studies space, stars, planets and asteroids, doesn't it?

The answer is D. Blackbody radiation. The piece of iron glows red because its temperature is around 1000 K, then yellow because its temperature is around 2800 K, and then white because its temperature is around 5500K. This shows that the spectrum of the radiation is determined by absolute temperature, as when the temperature of a blackbody radiator increases, the peak of the radiation curve moves to shorter wavelengths.