The correct answer is option 4, England. The concept of single citizenship in India is adopted from England. In England, individuals have only one citizenship and are not considered citizens of any specific region or state within the country. India followed a similar approach and adopted this concept from England when it established its own constitution. This means that all Indian citizens are considered citizens of the entire country and do not have separate citizenship based on their place of residence or origin within India. This concept promotes national unity and ensures that all Indian citizens have equal rights and privileges regardless of their regional or state affiliations.