Final answer:
Comparing the troposphere and the stratosphere, the stratosphere, being colder and higher, contains the least water vapor.
Step-by-step explanation:
The temperature zones of the earth atmosphere in question here are the troposphere and the stratosphere. The troposphere, which extends up to 12 kilometers above sea level, is where most weather events originate. This is largely due to the fact that the majority of the Earth's atmospheric water vapor is found in the troposphere, thus it is more dense and typically warmer. The stratosphere, on the other hand, which stretches from about 12 to 50 kilometers above sea level, is generally colder and free of clouds. In relation to your question, it is the stratosphere that contains the least amount of water vapor, given it is higher, colder, and cloud-free compared to the troposphere.
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