A particle moves anticlockwise in a horizontal circle centred at the origin. At t=0 it is at the point (r,0) and its velocity is along the +y-direction. After the particle has moved through an angular displacement of 120o, the directions of its velocity and acceleration respectively are
a) toward south-east and south-west
b) toward north-east and north-west
c) toward south-west and south-east
d) toward south-west and north-west