The correct answer is: C. 60-90o latitude.
The polar easterlies are a belt of easterly winds that blow from the poles towards the subtropics. They are found at high latitudes, between 60 and 90 degrees north and south of the equator. The polar easterlies are caused by the difference in temperature between the poles and the equator. The cold air at the poles sinks and flows towards the equator, while the warm air at the equator rises and flows towards the poles. This creates a circulation pattern that drives the polar easterlies.
The polar easterlies are important because they help to distribute heat around the globe. They also play a role in the formation of clouds and precipitation.
Option A is incorrect because the trade winds lie at 0-30 degrees latitude. Option B is incorrect because the mid-latitude westerlies lie at 30-60 degrees latitude. Option D is incorrect because the polar easterlies do not extend to the equator.