Final answer:
The angle of incoming sunlight is primarily responsible for climate variation in different parts of the world.
Step-by-step explanation:
The single feature primarily responsible for the variation of climate in different parts of the world is the angle of incoming sunlight. The angle at which sunlight hits the Earth's surface determines the amount of energy received, which in turn affects the temperature and climate. For example, areas closer to the equator receive more direct sunlight and therefore tend to have warmer climates, while polar regions receive sunlight at an oblique angle and have colder climates.
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