Which of the following indicates the correct order of the principal layers of the earth's atmosphere from top to bottom?

• A. Troposphere - Stratosphere - Mesosphere - Thermosphere - Exosphere
• B. Thermosphere - Stratosphere - Troposphere - Mesosphere - Exosphere
• C. Exosphere – Thermosphere - Mesosphere - Stratosphere - Troposphere
• D. Exosphere - Mesosphere - Thermosphere - Stratosphere - Troposphere