15 Regarding the process of German unification prior to 1871, which of the following statement is incorrect?
(A) The Customs Union led by Prussia helped to pave the way to national unification.
(B) Prussia, excluding Austria’s involvement, provoked the war against Denmark over sovereignty disputeof Schleswig and Holstein in 1864.
(C) Prussia adopted a lenient policy toward Austria after their war so as to reduce hatred and resistancefrom Austria.
(D) Napoleon III forced Prussia not to intervene into the succession of Spanish throne, resulting in theirworsening relationship and consequently into war.