Regional planning relates to which of the following?

The correct answer is Option 2: Area specific approach of development.

Regional planning focuses on the balanced and planned development of a particular region by considering its specific physical, economic, and social characteristics. Therefore, it follows an area-specific approach to development.

NCERT: "There is no uniform economic development over space in any country. Some areas are more developed and some lag behind. This uneven pattern of development over space necessitates that the planners have a spatial perspective and draw the plans to reduce regional imbalance in development. This type of planning is termed as regional planning."