Germany and italy became unified under a policy of realpolitik, a german expression that means that the goals of government policy should be accomplished by a. adherence to international law b. the calculated use of power c. following public opinion d. remaining true to ideals

The correct answer is B. the calculated use of power. A more precise answer would be the abandonment of ideology and ideals in favor of practical politics, which have often historically been tied to use of power. These are nothing more than examples of political realism as described by Hobbes and Machiavelli. By applying the power swiftly they managed to take control of not only their own countries, but of a large part of Europe too.