A walker starts from his home and follows this route: 200m east, 150m north, 120m west, and finally 150m south. He then stops. Which statement correctly gives both the total distance travelled and the magnitude of his displacement?
a) Distance=620m,displacement=0m
b) Distance=470m,displacement=80m
c) Distance=620m,displacement=80m
d) Distance=620m,displacement=200m