Read the excerpt from chapter 8 of The Travels of Marco Polo.

They have sheep here that have no ears, nor even ear-holes; but in the place where ears ought to be they have little horns. They are small creatures and very pretty. And here is something else that may strike you as marvelous: their domestic animals—sheep, oxen, camels, and little ponies—are fed on fish. They are reduced to this diet because in all this country and in all the surrounding regions there is no grass; but it is the driest place in the world. The fish on which these animals feed are very small and are caught in March, April, and May in quantities that are truly amazing. They are then dried and stored in the houses and given to the animals as food throughout the year. I can tell you further that the animals also eat them alive, as soon as they are drawn out of the water.

Why does the author include information about the dry climate?

to explain why the sheep have horns but no ears
to explain why the sheep in the region are so small
to explain why people in the region have to feed their animals fish
to explain why there are such large quantities of fish available