The correct answer is C) There were armed sentries posted at the camps.
Japanese Americans couldn't leave the camps because there were armed sentries posted at the camps.
After the Pearl Harbor attack of December 1941, the US entered World War II. President Franklin D. Roosevelt signed Executive Order 9066 to install internment camps to keed Japanese-Americans under heavy surveillance from 1942 to 1945. The Executive Order was signed on February 19, 1942, and many civil rights supporters consider it a violation of human rights.