The figure shows the velocity (v) of a particle plotted against time (t).Mark out the incorrect

The figure shows the velocity (v) of a particle plotted against time (t).
Mark out the incorrect statement.
(a) The displacement of the particle in time 2T is zero.
(b) The initial and final speeds of the particle are the same.
(c) The acceleration of the particle remains constant throughout the motion.
(d) The particle does not change its direction of motion.