The correct answer is option 4: South-East Asia.

In terms of culture, South-East Asia shares many similarities with India. This can be seen in various aspects such as religion, cuisine, festivals, and traditional practices. Both regions have been influenced by Hinduism and Buddhism, which have shaped their religious and philosophical beliefs. Additionally, Indian spices and cooking techniques have also made their way to South-East Asian cuisine.

However, when it comes to ethnicity, South-East Asia is closer to China. The majority of the population in South-East Asia shares genetic and cultural similarities with various ethnic groups in southern China. There have been historical and ongoing migration patterns between these regions, leading to the intermixing of cultures and ethnicities.

Central Asia, option 1, lies north of India and shares some cultural and historical connections, but its ethnic makeup is distinct from both India and China.

West Asia, option 2, is geographically closer to India, but it has its own unique cultural and ethnic identity that is different from both India and China.

Polynesia, option 3, is located in the Pacific region and has its own distinct culture and ethnic background, which is not closely related to India or China.

In conclusion, South-East Asia is the region that is culturally