Who developed the first successful printing press?

The correct answer to this question is A.

A printing press is a device for applying pressure to an inked surface resting upon a print medium (such as paper or cloth), thereby transferring the ink. It marked a dramatic improvement on earlier printing methods in which the cloth, paper or other medium was brushed or rubbed repeatedly to achieve the transfer of ink, and accelerated the process.

Typically used for texts, the invention and global spread of the printing press was one of the most influential events in the second millennium. Johannes Gutenberg, a goldsmith by trade, developed, circa 1439, a printing system by adapting existing technologies to printing purposes, as well as making inventions of his own.