The correct answer is option 4, which states that the approximate length of the coastline of India is 7,000 km. This means that if we were to measure the entire coastline of India, it would stretch for around 7,000 kilometers. The coastline of a country refers to the boundary where the land meets the sea. It is usually measured by tracing the outline of the land from one end to another, taking into account all the curves and bends. It is important to note that the measurement of a coastline can vary depending on the method used for measurement, such as considering only the mainland coastline or including the coastline of islands belonging to the country.