I believe it’s c, if not then a.
Answer:
On the first day of the war in 1914, British newspapers published appeals for young men to join the colours, and to fight against Germany. ... Men from all social classes and all areas of Britain volunteered. Others who were overseas in August 1914 traveled thousands of miles to get back and enlist.
Explanation:
This is unclear, but the best answer i can think of would be structure.