B. Depth creates the overall weight and more something is to be measured
C.collect common fossil evidence within the eurasian plate.
I am not sure about the second one, but I know the first one.
The answer is D.
"An irregular galaxy is a galaxy that does not have a distinct regular shape, unlike a spiral or an elliptical galaxy. Irregular galaxies do not fall into any of the regular classes of the Hubble sequence, and they are often chaotic in appearance, with neither a nuclear bulge nor any trace of spiral arm structure."