Question

Darkness settles on roofs and walls,

Answer 1

C, a mystery because the sea holds many unknowns

Answer 2

Answer:

C). Mystery.

Explanation:

Imagery is exemplified as the literary device that is employed to appeal to the senses of the readers and evoke the desired feelings from them. Such a device helps the audience by offering a visual representation through the use of diction that helps them to affiliate the complex ideas through these representations and understand it more conveniently and comprehensively.  

In the given lines, the author employs 'imagery' to invoke a sense of 'mystery' which is reflected through the use of words like 'darkness' settling on 'roofs and 'walls' and 'sea in darkness'. Thus, option C is the correct answer.