Answer:
The piece of evidence from the paragraph that best reveals Diaz's constant fear is 4. "An awful withering dread that coiled around my bowels — that followed me into my dreams." This description shows that the fear Diaz experienced was intense and persistent, as it not only affected him during his waking hours but also followed him into his dreams. The use of vivid language, such as "awful withering dread" and "coiled around my bowels," emphasizes the profound impact the fear had on Diaz's emotional and psychological state.