The most accurate response regarding the changes in the caste system in India and Pakistan is:
Caste-based discrimination has been outlawed.
While the caste system has seen changes and challenges over the years, including legal prohibitions against caste-based discrimination, it still persists in various forms in society. The other options provided do not fully reflect the complexities of the situation. For example, while there may be increases in women's rights, the hierarchical structure of castes remains largely intact. Additionally, the number of castes is not limited to three, as the caste system comprises numerous sub-castes and communities.