I agree. It's certainly not any of the other three!
personification
You are correct, the literary technique used in the line "That cold autumn morning no eyes saw the sun" is imagery. Imagery refers to the use of language to create a vivid sensory experience for the reader. In this line, the words "cold autumn morning" evoke a specific setting and atmosphere, allowing the reader to visualize and feel the scene. The phrase "no eyes saw the sun" further adds to the imagery by emphasizing the absence of sunlight, creating a sense of darkness or gloom.
