For $\vec { r } ( t ) = \langle \sin ( 3 t ) , \cos ( 3 t ) \rangle$

Multiple Choice

For $\vec { r } ( t ) = \langle \sin ( 3 t ) , \cos ( 3 t ) \rangle$ find the displacement vector as $t$ goes from $t = 0$ to $t = \pi$

A) $\langle - 2,0 \rangle$
B) $\langle - 1,0 \rangle$
C) $\langle 1,0 \rangle$
D) $\langle 1,1 \rangle$