The most accurate conclusion regarding the change in gender structures in early India from the early Vedic period to the late Vedic period is:
C. Women became socially isolated through purdah but retained rights to own property.
In the early Vedic period, women had relatively more freedom and rights, including participation in rituals and the ability to own property. However, as the society progressed into the late Vedic period, there was a noticeable shift towards increased patriarchy, including practices like purdah (the seclusion of women). Despite this, women continued to retain some rights over property, although their social roles and freedoms were increasingly restricted compared to earlier times.
The other options do not accurately reflect these changes as they either exaggerate the loss of rights or misrepresent the nuances of women's status during these periods.