I think it is answer choice E since the Gadsen Purchase was acquired last.
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.
Well i would assume this is a simile since the use of “as” and it’s comparing one thing to another :)
