Which statement is true of wind currents?

Formation of winds at the equator and polar region involves following few steps:

1. The warm air rises, and the cooler air from the regions in the 0–30 degrees latitude belt on either side of the equator moves in.

2. At the poles, the air is colder than that at latitudes about 60 degrees.

3. The warm air at these latitudes rises up and the cold wind from the polar regions rushes in, to take its place

4. A change in direction is, however, caused by the rotation of the earth.