Answer:
The line of poetry that best imparts a sorrowful mood is "O branches droop as gray skies loom".
Explanation:
Mood can be defined as the atmosphere an author creates that involves readers. Usually, word choice and description of the setting, as well as imagery, help produce a certain mood. Readers present an emotional response to the atmosphere - happiness, tranquility, fear etc.
Among the lines given in the question for analysis, the one that best conveys sorrow is the last one due to the word choice and imagery. The verb "droop" means to hang downward. Sadness is commonly related to drooping one's shoulders or head. The color used to describe the skies also transmits a dejected feeling. Usually, blue skies are associated to happiness, and gray, cloudy skies, with depression. Finally, the verb "loom" indicates something that appears as an unclear and frightening shape. All those elements contribute to a sorrowful emotional response from readers as they visualize the image described.
