Which of the following factors was not responsible for unification of India under Colonial rule?

The correct option is Socio-Cultural.

To understand why socio-cultural factors were not responsible for the unification of India under colonial rule, we can examine the impact of British policies across different dimensions:

1. Political Unification:
The British East India Company and, later, the British Crown brought the entire Indian subcontinent under a single political authority. This was achieved either through direct rule in British provinces or indirect suzerainty over the princely states, establishing a unified political entity with defined borders.

2. Administrative Unification:
The colonial administration established a highly centralized administrative structure. They introduced a uniform system of law and order, standardized judicial systems, and established professional services (such as the Indian Civil Service) that functioned systematically across the country.

3. Economic Unification:
The development of a nationwide transport and communication network—most notably the railways, postal system, and telegraphs—physically linked different regions. Additionally, a uniform currency and integrated trade policies created a single, national market out of previously isolated regional economies.

4. Socio-Cultural Factors:
Socio-cultural factors did not drive the colonial unification of India. Indian society remained highly diverse, fragmented by various religions, castes, languages, and regional traditions. Rather than unifying these elements, colonial policies often exploited existing social divisions (such as through the policy of "divide and rule") to maintain political control. Consequently, socio-cultural factors were not responsible for the unification of India under British rule.