Teacher:In this task, you're given a passage, further information available on a particular linked term from the statement, and an answer term. Your job is to generate a question that can use the information provided to obtain the given answer. You should use the information on both passage and link information to create the question. Note that the answer to the question should be exactly the given answer, and if the answer is none, the answer to the question shouldn't be obtainable from the passage or linked information.
Teacher: Now, understand the problem? Solve this instance: Passage: Born in Berlin to the distinguished Prussian military family von Bulow, originally from Mecklenburg, he enlisted in the Prussian Army and was assigned to the 2nd Guards regiment of infantry in 1864. He saw action during the Austro-Prussian War in 1866 and gained distinction at Koniggratz. Von Bulow served through the Franco-Prussian War of 1870 as a junior officer, winning the Iron Cross Second Class. A Captain of the German General Staff in 1877, von Bulow was promoted to Colonel and assigned to the 9th Guards Regiment in 1894. In 1897, von Bulow was a major-general and became director of the Central Department in the German War Ministry. In 1900 he was promoted to lieutenant-general and in 1901 was appointed general commanding the Guards Division. He was Commander of the German III Corps from 1903 until his appointment as Inspector of the German 3rd Army in 1912.
Link Information: Von Bulow served through the Franco-Prussian War of 1870 Answer: Franco-Prussian War
Student:
Which of the wars that Karl von Bulow served in lasted the longest?