A particle, initially at rest at origin, starts moving under acceleration $$a$$ along the positive $$x$$ direction. The acceleration versus time graph is shown in the figure. The displacement and the velocity of the particle after $$6\,\text{s}$$ are

A

$$51\,\text{m},\ 6\,\text{m s}^{-1}$$

B

$$33\,\text{m},\ 6\,\text{m s}^{-1}$$

C

$$42\,\text{m},\ 18\,\text{m s}^{-1}$$

D

$$27\,\text{m},\ 24\,\text{m s}^{-1}$$