I see you have a set of multiple-choice questions related to the layers of the atmosphere. Let's go through them step by step:
1. The layer of the atmosphere with the highest density of gas molecules is the Troposphere (marked as D in the options). This layer is where we live and where most weather phenomena occur. It contains approximately 75% of the atmosphere's mass.
2. In the Stratosphere, the relationship between temperature and altitude is that temperatures increase with an increase in altitude and become very hot (option C). This increase in temperature is due to the absorption of solar radiation by the ozone layer.
3. Pressure decreases rapidly with altitude because the air becomes less dense (marked as B). As you move higher in the atmosphere, there are fewer air molecules above pressing down, leading to a decrease in pressure.
4. The atmosphere helps sustain and protect life on Earth because the ozone layer shields us from harmful UV radiation (option A). This layer absorbs most of the sun's ultraviolet radiation, preventing it from reaching the Earth's surface and causing harm.
These answers should help you understand the different layers of the atmosphere and their characteristics. If you have any more questions or need further clarification, feel free to ask!
