A Projectile Starts at the Coordinate Origin,where the Displacement Vector $\theta$

Multiple Choice

A projectile starts at the coordinate origin,where the displacement vector also originates.The initial velocity,v₀,makes an angle $\theta$ ₀ with the horizontal where 0 < $\theta$ ₀ < 90 $\degree$ .At the instant when the projectile is at the highest point of its trajectory,the displacement,velocity and acceleration vectors are $\overrightarrow { \mathbf { r } }$ , $\overrightarrow { \mathbf { v } }$ and $\overrightarrow { \mathbf { a } }$ .Which statement is true?

A) $\overrightarrow { \mathbf { r } }$ is parallel to $\overrightarrow { \mathbf { v } }$ .
B) $\overrightarrow { \mathbf { r } }$ is perpendicular to $\overrightarrow { \mathbf { v } }$ .
C) $\overrightarrow { \mathbf { v } }$ is parallel to $\overrightarrow { \mathbf { a } }$ .
D) $\overrightarrow { \mathbf { v } }$ is perpendicular to $\overrightarrow { \mathbf { a } }$ .
E) $\overrightarrow { \mathbf { r } }$ is perpendicular to $\overrightarrow { \mathbf { a } }$ .