What must the Board include on each license and certificate?

The correct answer is that the license and certificate must include the signatures of the chairman and the secretary. This requirement serves a critical function in the validation and authenticity of the document. Including these signatures indicates that the license or certificate has been officially approved and issued by the governing body responsible for oversight, which in this case is the Board. The presence of the chairman's and secretary's signatures provides reassurance that the license has undergone the necessary review and meets all regulatory standards set forth by the Board.

This aspect is vital for maintaining the integrity of the licensing process and upholding public trust in the regulatory framework governing professional practices. Other elements such as the date of issuance or continuing education details might be important but do not carry the same weight in terms of authentication and approval as the signatures do.