Cómo y por qué surge el arte contemporáneo?

The adjective contemporary works as a broad umbrella under the which everything what happened during the twentieth century has no place. And , in the case of art , the same thing happens. We refer to contemporary art when we talk about the artistic trends and styles that took on a special role in the different decades of the last century.

Explanation:

c.) the country needed a stronger central government.

porter is writing economic history because he is focusing on the cost of developing vaccines.