Answer:
Among the options given on the question the correct answers are A, B,C,
travelers from foreign lands add diversity
Small settlements often become large trade centers.
Fishing is usually an important industry
Explanation: In coastal area normally people from different countries come for trade and business which is operated through sea ways. As a result the travelers from foreign land often stay on the coastal area and their life style often creates diversity mixing with the local people.
Coastal areas often become large trade centers. From ancient time sea ways are used a route of trade. Coastal areas are used as the exchanging point of goods.So often a small settlements becomes a large trade center.
Moreover people living on the coastal area is based on the fishing occupation. So people related with fishing industry goes to the coastal area. As a result it is an important industry in the coastal area.