Which of the following might cause a new core area to develop?

A rise in the cost of living
New transportation infrastructure
The discovery of natural resources
Tariffs and barriers on trade
I and II
I and III
II and III
II and IV
III and IV

explanation:

on august 6, 1945, just days after the potsdam conference ended, the u.s. bomber enola gay dropped the uranium bomb known as “little boy” on the japanese city of hiroshima. despite its devastating effects, japan didn't offer unconditional surrender right away, as the united states had hoped.