Answer:
Cruel darkness crept o'er the stern.
Step-by-step explanation:
Personification is a literary device which is used to personify unhuman things with human characteristics. This literary device is used to epitomize human characteristics such as behaviour, feelings, emotions, etc to objects that are non-living, ideas, unhuman things, etc.
From the given excerpt, the line in which the writer has used personification is in the last line (4th line) 'Cruel darkness crept o'er the stern .' Cruelity is a human trait, which is used to personify 'darkness', a non-human object.
Therefore, option D is correct.