Concept:The length of a state's coastline is the distance where its land meets the sea. Gujarat has the longest coastline among all Indian states.Explanation:Gujarat’s coastline stretches about 1,600 km along the Arabian Sea. This is longer than the coastlines of Tamil Nadu (approx. 1,076 km), Andhra Pradesh (approx. 972 km), and Maharashtra (approx. 720 km). Important ports like Kandla, Mundra, and Pipavav lie on Gujarat’s coast. The state’s long shoreline supports trade, fishing, and tourism. Therefore, Gujarat is the correct answer.Answer:A. Gujarat