Which of the following is most  accurate about Europe during…

Which of the following is most  accurate about Europe during World War I?   a.  Long-standing nationalistic and imperialistic rivalries produced a dangerous political situation.    b.  The continent had experienced several major wars in the preceding decades.    c.  Industrialization and a greater commitment to international trade had created rapidly rising standards of living.    d.  There was rising solidarity among the labor movements of different nations.