Correct Answer:
B. Act itself
Grantees who receive proprietary rights are fundamentally bound by the conditions stipulated within the Act itself that authorizes such grants. While the Collector may enforce these conditions and the Board of Revenue (BoR) might provide oversight, the ultimate legal authority and the specific terms governing the proprietary rights originate from the enabling legislation. The "Original conditions" might be part of the grant document, but their legal enforceability and framework are derived from the Act. Therefore, the Act serves as the primary source of binding conditions for such grantees.