This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.

Input: Consider Input: Passage: The strategy behind the formation of the Warsaw Pact was driven by the desire of the Soviet Union to dominate Central and Eastern Europe. This policy was driven by ideological and geostrategic reasons. Ideologically, the Soviet Union arrogated the right to define socialism and communism and act as the leader of the global socialist movement. A corollary to this idea was the necessity of intervention if a country appeared to be violating core socialist ideas and Communist Party functions, which was explicitly stated in the Brezhnev Doctrine. Geostrategic principles also drove the Soviet Union to prevent invasion of its territory by Western European powers. Question: The Soviet Union feared invasion from which potential enemy?

Output: Western Europe


Input: Consider Input: Passage: However, since the end of the Cold War, as the North Atlantic Treaty Organization (NATO) has moved much of its defence focus "out of area", the Canadian military has also become more deeply engaged in international security operations in various other parts of the world – most notably in Afghanistan since 2002. Question: What Treaty is the CAF part of?

Output: the North Atlantic Treaty Organization (NATO)


Input: Consider Input: Passage: Evidence suggests that blast furnaces, that convert raw iron ore into pig iron, which can be remelted in a cupola furnace to produce cast iron by means of a cold blast and hot blast, were operational in China by the late Spring and Autumn period (722–481 BC). The bloomery was nonexistent in ancient China; however, the Han-era Chinese produced wrought iron by injecting excess oxygen into a furnace and causing decarburization. Cast iron and pig iron could be converted into wrought iron and steel using a fining process. Question: What type of process was used to convert various metals into steel?


Output: fining