Which among the following is the highest layer of atmosphere when measured from the sea level?

Exosphere

The correct answer is Option (3) → Exosphere

The highest layer of the atmosphere when measured from sea level is the Exosphere.

The Earth's atmosphere is divided into five main layers based on temperature and composition. Starting from sea level and moving upward, they are:

1. Troposphere: (0 to 12 km) The lowest layer where we live and where all weather occurs.
2. Stratosphere: (12 to 50 km) Contains the ozone layer which protects us from UV radiation.
3. Mesosphere: (50 to 85 km) The layer where most meteors burn up upon entry.
4. Thermosphere: (85 to 600 km) Home to the International Space Station and the Aurora Borealis.
5. Exosphere: (600 to 10,000 km) The outermost edge of our atmosphere.