Answer:
The correct answers are:
1. he strengthened the army with the money collected for other purposes, in order to lead an aggressive foreign policy
2. he attacked Austria without reason
3. he involved Napoleon III into war in Prussia
Step-by-step explanation:
The Realpolitik refers to realistic politics based on the needs of the state and considerations of given circumstances. The first German Chancellor, Otto von Bismarck used the Realpolitik to achieve Prussian dominance in Germany by antagonizing other countries and causing unnecessary wars to achieve his goals.
Therefore, he strengthened the army with the money collected for other purposes, to lead an aggressive foreign policy that would unify Germany in the 19th century. For the same reason, he decided to attack Austria and to involve Napoleon III into war in Prussia.