Correct Answer: Exosphere

Solution : The correct option is Exosphere.

The exosphere is the Earth's outermost layer of atmosphere. It progressively expands beyond the thermosphere and unites with the emptiness of space. The exosphere is distinguished by extremely low gas molecule concentrations and a slow transition into the vacuum of outer space. The Earth's atmosphere is divided into layers, each with its own set of qualities and functions: the troposphere, stratosphere, mesosphere, thermosphere, and exosphere.