Pick out the wrong statement.

• The concentric layer in atmosphere which contains about 70% of the total mass of atmosphere and characterised by a steady decrease in temperature is called stratosphere.
• Stratosphere is rich in ozone and is located just above the troposphere.
• Troposphere is a turbulent dusty zone containing much of water vapor and clouds.
• The earth's atmosphere is an envelope of gases extending upto a height of about 200 kms.