Answer:
The likely inspiration for writing "Vigil Strange I Kept on the Field One Night” is:
B. His experience as a nurse during the Civil War.
Step-by-step explanation:
Walt Whitman's participation in the American Civil War was as a nurse. After learning his own brother had been injured by shell particles, Whitman volunteered as nurse. He rushed to his brother side to take care of him and, in the end, spent three years helping other soldiers as well. Whitman's brother, George Washington Whitman, did not die during the war, so we can eliminate the first option in the question. We can also eliminate letter D, since we know Whitman himself was not a soldier. We are left with options B and C. Critics and scholars diverge when it comes to the poem "Vigil Strange I Kept on the Field One Night”. But, in general, most of them agree that the sad image of a soldier standing vigil for his dead friend or family member originated in his experiences during war. Some say Whitman himself did that for a friend of his, some say he saw it happen. No one knows for sure, but we can safely eliminate letter C. The best option is, therefore, letter B. His experience as a nurse during the Civil War.