Which of the following might cause a new core area to develop? I. A rise in the cost of living
II. New transportation infrastructure
III. The discovery of natural resources
IV. Tariffs and barriers on trade

I and II
I and III
II and III
II and IV
III and IV

II and III

Explanation:

I: Why would people pay more to live somewhere?

II: People like accessibility, so it makes sense that they want to live somewhere where there is good infrastructure

III: People will be drawn to the potential to make money off of the natural resources and/or related work in the field of extraction of said natural resource.

IV: Nobody would want to live an an economy that is in shambles, and that they have to pay more for simple things due to immence trade restrictions.

II and III are correct, where I and IV simply are not.

i think its toxic gasses but i could be wrong