The correct answer is option 3: Tundra. Yakuts are actually not nomadic herders but an indigenous group of people who live in the Sakha Republic, which is located in the extreme northeast of Russia. The Sakha Republic encompasses a large part of the Siberian region, where the climate is predominantly tundra.

Tundra is a type of biome characterized by its cold temperatures, short growing seasons, and vast areas of barren land. It is mostly devoid of trees and consists of mosses, lichens, and low-growing shrubs. Yakuts traditionally rely on reindeer herding as their main livelihood, as reindeer are well adapted to survive in the harsh tundra environment.

Options 1, 2, and 4 are incorrect. The Gobi Desert (option 1) is located in Mongolia and China and is mainly characterized by arid and desert conditions. The Sahara Desert (option 2) is the largest hot desert in the world, located in northern Africa. The Kalahari Desert (option 4) is a large sandy savannah in southern Africa. None of these options accurately represent the habitat and lifestyle of Yakuts.