Which of the given layer of the atmosphere has the lowest density?

Correct option is B

​The correct answer is (b) Exosphere.​

• The exosphere is the outermost layer of Earth's atmosphere, extending from about 600 km above Earth's surface to around 10,000 km or more.
• This layer contains extremely sparse gases, primarily hydrogen and helium.
• The density of air molecules in this layer is the lowest compared to all other atmospheric layers.

Information Booster:

• Ionosphere : Part of the thermosphere and mesosphere, it contains ionized particles and has a higher density than the exosphere.
  
• Stratosphere : A denser layer than the exosphere, located closer to Earth (10-50 km altitude). It contains ozone and supports jet streams.
• Mesosphere : Found above the stratosphere (50-85 km altitude), it is denser than the exosphere but thinner than the troposphere and stratosphere.