Population density is a measurement of population per unit area, or exceptionally unit volume; it is a quantity of type number density. It is frequently applied to living organisms, most of the time to humans. It is a key geographical term. Hope this answered your question
Um, Im not sure try this website
http://www.infoplease.com/encyclopedia/us/washington-state-united-states-geography.html
I think the correct answer from the choices listed above is the second option. An archaeologist studies the lives of early humans by examining artifacts. It studies the human activity by recovering and analyzing of material remains. Hope this answers the question. Have a nice day.
