Assertion: In ancient India 'kanyadana' or the gift of a daughter in marriage was an important religious duty of the father.
Reason: In ancient times, the lives of young girls and women belonging to families that claimed high status were often carefully regulated to ensure that they were married at the right time and to the right person.

Both the Assertion and the Reason are correct and the Reason is the correct explanation of the Assertion.

In ancient India, the role of sons was crucial for the continuity of the patrilineage, whereas daughters were perceived differently within this societal structure. Unlike sons, daughters did not hold any claims to the household's resources. However, marrying daughters into families outside their own kin was considered desirable, following the practice known as exogamy, or marrying outside one's social group. Consequently, the lives of young girls and women from high-status families were carefully regulated to ensure they were married at the appropriate time and to suitable partners.

This practice of regulating marriages gave rise to the belief that the act of kanyadana, or giving away a daughter in marriage, held significant religious importance, becoming a vital religious duty for the father. This belief further reinforced the idea that the marriage of daughters was not merely a social arrangement but had profound religious significance. Thus, the system of exogamy and the religious duty of kanyadana were deeply ingrained in ancient Indian society, shaping the lives and destinies of young girls and women from high-status families.