Q. Which is the warmest layer of the atmosphere?

[A] Thermosphere

[B] Troposphere

[C] Stratosphere

[D] Mesosphere

Answer: A
Notes:

The thermosphere is the layer of the Earth’s atmosphere directly above the mesosphere. It extends from about 90 km to 1,000 km above our planet. In thermosphere temperature can reach up to 4,500 degrees Fahrenheit. Thus making it the warmest layer of the atmosphere.

Source: NCERT