Answer:
B.a book written during the time period
Step-by-step explanation:
The most appropriate primary source for Walter to use in his research on the influence of World War II on literature during the time period would be a book written by a soldier who fought in the war. This is because primary sources provide firsthand accounts of events and experiences, which can give Walter a more accurate and nuanced understanding of the topic than secondary or tertiary sources.
Primary sources can be defined as documents or artifacts that were created during the time period that you are researching. They can include letters, diaries, memoirs, newspaper articles, government documents, photographs, paintings, songs, and poems. Secondary sources are accounts of events and experiences that were written after the time period in question. They can include textbooks, biographies, and scholarly articles. Tertiary sources are encyclopedias, indexes, and other reference works that summarize information from primary and secondary sources.
In the case of Walter's research, a book written by a soldier who fought in the war would be a primary source that could provide him with insights into the experiences of people who lived through the war. He could learn about the challenges and hardships that people faced, as well as their hopes and dreams for the future. He could also see how the war influenced the way people thought about the world and their place in it.