What technology is used to study the night sky?

Witch one is it soo it the the question b.a,b,c,d

If we represent the solar system on a scale that allows us to walk from the sun to pluto in a few minutes, then a) the planets are microscopic and the stars are millions of miles away. b) the planets are the size of basketballs and the nearest stars are a few miles away. c) the planets are marble size or smaller and the nearest stars are thousands of miles away.

According ti the following map, what are the most common mineral resources found in the united states?