If `vec F` is the force acting in a particle having position vector `vec r` and `vec tau` be the torque of this force about the origin, then

Options

A. `vec( r ) . vec( T ) = 0` and `vec(F) .vec(T)=0`
B. `vec(r ) .vec(T) cancel(=)` but `vec(F).vec(T)=0`
C. `vec(r ) .vec(T) cancel(=)` but `vec(F).vec(T)cancel(=)0`
D. `vec( r ) . vec( T )cancel( =) 0` and `vec(F) .vec(T)cancel(=)0`

Answer

A