Which is not a public document under the Act? 

Under the Bhartiya Sakshya Adhiniyam, public documents include records of acts or decisions of public officers or government bodies, such as FIRs, gazette notifications, court judgments, and municipal notifications. A will, even if registered with a sub-registrar, remains a private document, as it pertains to individual affairs and not to the functioning of public authorities. It does not fall under public record maintenance or disclosure duties. Hence, Option C is correct since a registered will, although authentic, does not convert into a public document merely by registration and remains within the domain of private legal instruments.