Which is the best reason that explains why american cities exist where they do today?
people choose areas that are pleasing to the eye
cities begin where suburban growth is well established.
cities begin where there are easily obtainable resources available.
people choose areas where resources are limited and difficult to obtain.

C) Cities begin where there are easily obtainable resources available.

Explanation:

Let's start by process of elimination.

Right off the bat, we can get rid of D- why would someone want to live somewhere difficult if there's tons of other places to live where life can be easier?

Living conditions are far more important than the natural beauty when it comes to settling, to we can knock A off too.

Now, we're left with two choices- where suburban growth is well-established, and where there are easily obtainable resources available.

The thing about suburbs is that they didn't really come around until cities did. I mean, it's in the name- sub (secondary) urban (city).

It's C. Tons of cities were established expressly for obtaining natural resources and because of convenience.