What can scientist learn from moon rocks?

Question

A. The moon's water supply evaporated in recent years

B. The moon is denser than earth
C. The moon is older than the Earth
D. The moon and earth are made of similar material

let me see A and C are wrong cause a say the moons watre supply evap. in rec. years but there no water in the moon. and c is wrong because i think the earth is older

Since this is not my area of expertise, I searched Google under the key words "moon earth compar" to get these possible sources: (I did not complete the last word, so it would relate to both "compare" and "comparison.")

http://commons.wikimedia.org/wiki/Image:Moon_Earth_Comparison.png
http://sse.jpl.nasa.gov/planets/compchart.cfm?Object1=Moon
http://www.enchantedlearning.com/subjects/astronomy/moon/
http://nssdc.gsfc.nasa.gov/planetary/factsheet/moonfact.html

In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search.

I hope this helps. Thanks for asking.