A particle is kept fixed on a turntable rotating uniformly. As seen from the ground,the particle goes in a circle, its speed is 20cm/s and acceleration is 20cm/s The particle is now shifted to a new position to make the radius half of the original value. The new values of the speed and acceleration will be
(a) 10cm/s, 10cm/s2
(b) 10cm/s, 80cm/s2
(c) 40cm/s, 10cm/s2
(d) 40cm/s, 40 cm/s2.