Which climate zone would be characterized by extensive low-growing vegetation due to cold temperatures?

The tundra climate zone is characterized by cold temperatures and a unique ecosystem that supports low-growing vegetation, such as mosses, lichens, and small shrubs. The extremely low temperatures and short growing seasons limit the types of plants that can survive in this environment, leading to a landscape dominated by these hardy species.

In the tundra, the ground is often permanently frozen (permafrost), which further restricts root growth and the types of vegetation present. This is in sharp contrast to desert climates, which have very little vegetation due to lack of moisture, and tropical climates, which are known for their lush, dense forests and warm temperatures. Temperate climates support a broader variety of flora, including deciduous and coniferous trees, and have more moderate temperatures, unlike the extreme cold found in the tundra. Thus, the characteristic low-growing vegetation of the tundra zone is the defining feature that makes it the correct answer.