If $\overrightarrow{F}$ is the force acting on a particle having position vector $\overrightarrow{r}$and $\overrightarrow{\tau}$ be the torque of this force about the origin, then :

Question

( A ) $\overrightarrow{r}.\overrightarrow{\tau}=0$ and $\overrightarrow{F}.\overrightarrow{\tau}\neq0$
( B ) $\overrightarrow{r}.\overrightarrow{\tau}\neq0$ and $\overrightarrow{F}.\overrightarrow{\tau}=0$
( C ) $\overrightarrow{r}.\overrightarrow{\tau}>0$ and $\overrightarrow{F}.\overrightarrow{\tau}<0$ <br/> ( D ) $\overrightarrow{r}.\overrightarrow{\tau}=0$ and $\overrightarrow{F}.\overrightarrow{\tau}=0$