Direction: Read the Passage given below and answer the questions that follow by selecting the most appropriate option-

Every year, a large number of Siberian cranes come to the bird sanctuary at Bharatpur. Year after year, in the beginning of winter these birds cover thousands of miles from Siberia in the north of Russia to come to Bharatpur, and then, as winter ends, they once again return to their original habitat, without making any mistake in the direction they have to take in their long flights. It is surprising how these birds find their way over such long distances, especially when vast stretches of land happen to be covered with clouds so that familiar landmarks, which could have guided them, are not even visible. The same phenomenon has been observed in other parts of the world as well. By way of experiment, light metal rings with specific information are put on the legs of some migratory birds, and it is observed that they keep returning to the winter sanctuary year, after year without fail. Pigeons are well known for finding their way back home inspite of all odds. At one time, it was believed that they could find their way with the help of familiar landmarks which they had seen and remembered. In an experiment, some pigeons were carried to a considerable distance in cages covered with black cloth so that they could not see anything on the way. However, when they were released, they still managed to come back to the place from where they had been taken away in covered cages. To check whether the pigeons remembered the direction of movement even when they could not see anything, another experiment was undertaken. To confuse their sense of direction, some pigeons were carried in an aeroplane and then released, Many of them still managed to return home on their own.