Which sentence from the article BEST summarizes one of the article's CENTRAL ideas? A
During the American Civil War, Williams had worked as a cook and washer for the Union.
B
When the war ended, Williams disguised herself as a man in order to join the military as a soldier.
C
In January 1868, her health declined and she was admitted to hospitals five times.
D
In the 2002 book "Cathay Williams: From Slave to Female Buffalo Soldier," historian Phillip Thomas Tucker attempted to document Williams’ life.