Questions: In the mid-1400s, Gutenberg made books more accessible by using A the bookbinder. B movable type. C the fountain pen. D engraving plates.

The answer is B: movable type.

Explanation for each option:

A. The bookbinder - Incorrect. Bookbinding is the process of physically assembling a book from an ordered stack of paper sheets, but it does not relate to the invention that made books more accessible. Gutenberg's contribution was not in bookbinding.

B. Movable type - Correct. Johannes Gutenberg is credited with the invention of the movable type printing press around 1440. This innovation allowed for the mass production of books, making them more accessible and affordable to the general public. It revolutionized the way information was disseminated and played a crucial role in the spread of knowledge during the Renaissance.

C. The fountain pen - Incorrect. The fountain pen is a writing instrument that was developed much later, in the 19th century. It is unrelated to the printing process or the accessibility of books in the mid-1400s.

D. Engraving plates - Incorrect. Engraving plates are used in a different printing process known as intaglio, which involves etching or engraving a design onto a surface. While engraving was used for illustrations and some texts, it was not the method that Gutenberg used to make books more accessible. His use of movable type was the key innovation.