Which pioneers in printing introduced the first book to bear a printer's trademark in 1457?

The pioneers in printing who introduced the first book to bear a printer's trademark in 1457 were Johann Fust and Peter Schoeffer. This landmark event marked a significant advancement in the printing industry as it added a layer of identification and credibility to printed works. The book they produced, a Psalter (the Book of Psalms), featured the printer's mark, showcasing the growing importance of publishers and the print medium in society.

Fust was an investor in Gutenberg's printing enterprise, and alongside Schoeffer, he contributed to further refining the technology and processes of movable type printing after Gutenberg’s initial innovations. This partnership is crucial in the history of printing, as it laid the foundation for publishers to differentiate their works, ensuring quality and reputation became integral to the industry.

The other figures mentioned in the choices either played roles in different eras or contexts of printing and publishing or were not directly associated with the landmark achievement attributed to Fust and Schoeffer.