among the given statements, only (A) is true. Key Points Water, air, land and all living things make up the four domains of the earth. A domain is a region that has its own special features. The four domains of the earth are explained below: Lithosphere: The solid portion of the earth is called the Lithosphere. It comprises the rocks of the earth’s crust and the thin layers of soil that contain nutrient elements which sustain organisms. Hydrosphere: Water covers a very big area of the earth’s surface and this area is called the Hydrosphere. The Hydrosphere comprises water in all its forms, that is, ice, water and water vapour. Atmosphere: The atmosphere is the thin layer of air that surrounds the earth. The gravitational force of the earth holds the atmosphere around it. It protects us from the harmful rays and scorching heat of the sun. It consists of a number of gases, dust and water vapour. Biosphere: Plant and animal kingdom together make biosphere or the living world. It is a narrow zone of the earth where land, water and air interact with each other to support life. Based on the above discussion, we can conclude that the following statement is correct: A. The gravitational force of earth holds the atmosphere around it