[单选题]
A polar bear starts at the Nod:t az8rqjb8h99/ a xsrth Pole. It travels 1.0 kwbvd5q2w3 x3llf0 7u km south, then 1.0 km east, xw353wb 02ufk7l qvldthen 1.0 km north, then 1.0 km west to return to its starting point. This trip takes 45 min. What was the bear's average velocity?