I need help with these 2 geology questions

Which of the following areas has the highest population density?

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.

What is the difference between the formation and characteristics of intrusive igneous rock and extrusive igneous rock?