Final answer:
The lowest layer of Earth's atmosphere is the troposphere, which extends up to about 11-13 km in altitude and is where most of our weather occurs. The correct answer to the question is D.
Step-by-step explanation:
The troposphere is the lowest layer of Earth's atmosphere. This layer extends from Earth's surface to an altitude of about 11-13 km (7-8 miles), where most of our weather phenomena occur. The temperature of the troposphere decreases with increasing altitude. Above the troposphere is the stratosphere, which is known for containing the ozone layer that protects us from harmful ultraviolet radiation. While the ionosphere is part of the upper atmosphere, it is not a distinct layer like the troposphere; instead, it overlaps with the mesosphere and thermosphere and is known for its ionized particles, which are important for radio communication.
The correct answer to the question is D.