How can we say that the Constitution of India seeks to unify India?

The correct option is: It was designed to keep the country’s divided classes, communities and castes together.

Explanation:

At the time of India's independence in 1947, the nation was deeply fragmented by diverse social divisions. The country was home to various religious communities, hundreds of linguistic groups, numerous castes, and distinct socio-economic classes, many of which had historical conflicts or inequalities.
The framers of the Constitution of India recognized that for the newly independent nation to survive and progress as a single, sovereign country, it was crucial to build a framework of unity. Therefore, they deliberately designed the Constitution to accommodate this vast diversity.

To achieve this unification, the Constitution incorporated several key features:
1. Fundamental Rights and Equality: It guarantees equality before the law and prohibits discrimination on the basis of religion, race, caste, sex, or place of birth (Articles 14-18). This helped bring historically marginalized castes and classes into the mainstream.
2. Abolition of Untouchability: By legally abolishing untouchability (Article 17), the Constitution took a major step toward healing deep social divides and promoting social integration.
3. Secularism: By ensuring that the state has no official religion and treats all religions equally, it provided reassurance to diverse religious communities, fostering a sense of shared belonging.
4. Universal Adult Suffrage: By granting the right to vote to every adult citizen regardless of their wealth, education, gender, caste, or religion, it politically unified all citizens under a single democratic system.

Thus, the Constitution seeks to unify India primarily because it was structured as a social and political contract designed to bind together the country’s diverse and divided classes, communities, and castes into a single, cohesive nation.