All galaxies have a dense core of stars. Spiral galaxies, however, have arms that are often visible. There are two kinds of spiral galaxies: barred, where there appears to be a line running from arm to arm through the core, and <span>ordinary, where there is no bar. @Badbunnyhunny</span>
Hadean is the first eon of precambrian, and took place around 4.6 and 4.0 billion years ago.
It would be A, because a fossil forms after an animal dies, and hundreds to thousands of years of soil or sediment coversit's body, preserving it. :)
It may be 166, but you may want to check my math
