Answer: A) the heading "Gutenberg" at the top of the paragraph
Explanation: Adding the heading "Gutenberg" at the top of the paragraph will help and aid readers in understanding what the paragraph is talking about. You do not necessarily need a map of Germany or a black and white photograph of a letter used in Gutenberg's printing press, also you do not need an artist's rendering of the Gutenberg printing press to understand the paragraph. However writing the heading "Gutenberg" makes a reader curious to read the paragraph.