The correct answer is option 3, Silk. In the given map, the textile industries are represented by black dots. Option 1, Cotton, is not represented by black dots in the map. Cotton is a widely used textile industry, but it is not specifically represented in this map. Option 2, Jute, is also not represented by black dots in the map. Jute is a natural fiber used in producing items like bags and ropes, but it is not depicted in the map. Option 4, Woollen, is not represented by black dots in the map. Woollen refers to the textile industry that produces fabrics made from the fleece of sheep or other animals, and it is not visually indicated in this map. Therefore, the correct answer is option 3, Silk, as it is the only textile industry represented by black dots in the given map.