Veolocity-time graph of a particle undergoing rectilinear motioin is plotted upto `t=t_(4)` as shown in the figure. Average acceleration of the particle is zero in the time internal between
A. 0 and `t_(1)`
B. `t_(1)` and `t_(2)`
C. `t_(1)` and `t_(3)`
D. `t_(3)` and `t_(4)`