Answer: BAruns back was positioned towards the sun.
Thus, depending on the time of the day, Arun could have been walking towards the West(morning) or towards the East(evening).
Case I : Arun was walking towards the West.
Thus, he finally faces the south.
Case II : Arun was walking towards the East.
Thus, he finally faces the north.
Hence, Arun could have been going either towards the South or towards the North.