A. troposphere, tropopause, stratosphere, stratopause, mesosphere, mesopause, ionosphere(thermosphere, thermopause, exosphere)
B. troposphere, stratosphere, stratopause, mesosphere , ionosphere
C. troposphere, tropopause, stratosphere, thermosphere, exosphere
D. troposphere, tropopause, stratosphere, mesosphere , exosphere, thermosphere, thermopause}
✅ The correct answer is option A.