Answer:
B. caused a boom in membership.
The Knights of Labor's 1885 strike against the Missouri Pacific Railroad was an overall success for the union because there was an increase in its Membership as it soared to 700,000 including 600,000 African Americans.
Americans began to wonder if they could win the war. During the beginning of the war, morale amongst Americans was generally high and accepted a quick victory against the Viet Cong. As time went on however, fighting in the unknown terrain of Vietnam against an enemy who had no true uniform and blended in with the locals made fighting very difficult which prolonged the war. In 1968, the Viet Cong launched a nationwide surprise attack in cities, in the countryside, by splinter groups who all coordinated assaults in South Vietnam known as the Tet Offensive. The attack was a failure for the Viet Cong, but for the Americans to see the size and scope of the surprise attack in areas originally thought to be under US and South Vietnamese control was a psychological blow for the American military. They soon realized that fighting an enemy who they could not identify regardless of the hostile or friendly terrain eventually influenced the Americans decision to pull out of the war in 1973.
The answer to your second question is D.) Welfare