When water vapor is transported to the upper atmosphere and begins to coalesce, the interaction of this vapor with aerosols and dusts produce . Continued transport (Northward or upward) and interactions with ice crystals can often produce .

The atmosphere always experience the change of mixtures which are present giving rise to different phenomenons and for that reason many climate changes inside the different regions are also experienced.As, we see that there is a gaseous like formation which are due to the presence and mixing of the upper atmosphere and begins to coalesce, the interaction of this vapor with aerosols and dusts produce clouds.Continued transport (Northward or upward) and interactions with ice crystals can often produce glaze. Across, the globe there are different levels of environmental conditions giving rise to difference in temperature, air properties, and more over the effect of the environment on the living beings.

The answer is a but it also might be 7 so

Answerhave flowing water either episodically or during only a portion of the year;