The correct answer here is the option D.
Tet offensive was a major offensive undertook by the Viet Cong along with the North Vietnamese People's Army of Vietnam and it showed the shocked South Vietnam and its American allies that the war was actually far from over. This also led to the loss of the support for the war in the States.
I think it’s c is the answer
Before the Civil War, cotton was the primary income to every Southern State, but after the enslaved workers were free the cotton growing/cotton picking business was burned into the ground because no one was able to be found to work the fields.
Look up a summary of the book online.
The answer would be A I Believe. AN AGREEMENT TO ALLOW MEXICAN WORKERS INTO THE US FOR ONE YEAR.