But in my opinion is option D. Because fishes are easily available and cheaper than mutton in coastal areas. Mutton are the food items are consumed mostly by rich people in plain areas.

Coastal areas are regions located near the coastlines of oceans, seas, or other large bodies of water. These areas have unique geographical features and climatic conditions that influence the types of crops grown and the diet of the people living there. In this case, the correct answer is option 'C', which states that people living in coastal areas eat rice and fish. Let's explore the reasons behind this answer in detail.

Benefits of Rice in Coastal Areas:
- Rice is a staple food for many people around the world, including those living in coastal areas. It is a versatile grain that can be cooked in various ways and provides essential nutrients and energy.
- Coastal areas often have fertile soil that is suitable for rice cultivation. The presence of water bodies such as rivers, lakes, or the ocean itself allows for irrigation and ample water supply required for the growth of rice crops.
- The climate in coastal areas is generally humid, which is favorable for rice cultivation. Rice requires a significant amount of water and warm temperatures to thrive, making coastal regions ideal for its growth.

Importance of Fish in Coastal Areas:
- Coastal areas are rich in marine resources, including various species of fish. Fishing has been a traditional occupation and a major source of livelihood for people living in these regions.
- Freshwater bodies like rivers and estuaries in coastal areas provide habitats for fish to breed and grow. The proximity to the ocean allows for easy access to a wide variety of fish species.
- Fish is an excellent source of protein, omega-3 fatty acids, vitamins, and minerals. It is a nutritious food option for people living in coastal areas, especially when combined with rice.

Dietary Habits in Coastal Areas:
- The combination of rice and fish forms a significant part of the diet in coastal areas. This combination provides a balanced diet with carbohydrates from rice and protein from fish.
- Other seafood like shellfish, crabs, and shrimps are also commonly consumed in coastal areas due to their availability and nutritional value.
- The presence of rice and fish in the diet of coastal communities reflects the traditional food habits influenced by geographical factors, cultural practices, and availability of resources.

In conclusion, people living in coastal areas primarily consume rice and fish as these foods are readily available, well-suited to the climatic conditions, and contribute to a balanced diet.