The climate region labeled with the number 1 on the map above is the region

The climate region labeled with the number 1 on the map above is the ARID region

Explanation:

A region is arid when it is characterized by a severe lack of available water, to the extent of hindering or preventing the growth and development of plant and animal life.Arid regions by definition receive little precipitation—less than 10 inches (25 centimeters) of rain per year. Semi-arid regions receive 10 to 20 inches (25 to 50 centimeters) of rain per year. Most of the world's arid climates lie just north and south of the tropical rain forests of the equator. Mountain plateaus are another location where you might find an arid climate. The southwestern corner of the United States, for example, is quite dry and hot.Cold currents carry dry air, so these lands are blasted with dry air most of the year, which causes the low precipitation.Environments subject to arid climates tend to lack vegetation and are called xeric or desertic.

I'm pretty sure it's c. extremely gradual but not 100% sure though.

Answer were lower;