Tropical and polar climate zones are very distinct. This is because _____.?

1)the Sun's rays are more concentrated near the equator
2)the Sun's rays are more concentrated near the poles
3)the poles absorb sunlight more effectively
4)clouds reflect more sunlight at the equator

If the poles absorbed sunlight more effectively then the regions where the poles are would be hotter. But because the the sun's rays are more concentrated near the equator this is the region where it is hot and tropical.