Consider a shell rolling purely on a horizontal fixed surface.  The velocity of the centre of Shell is  $v_0\widehat{i}$  and acceleration of the centre of shell is  $a_0\widehat{i}$ .   
 
Following representative point are chosen on the shell 
P (on z-axis)
Q and R (on x-axis)
S (on y-axis)
Following symbolic representation has been used
$\overrightarrow{r}=$  position vector of a point with respect to  $o$ on ground
$\overrightarrow{v}$ =velocity vector of point with respect to ground 
$\overrightarrow{\omega }=$  angular velocity of the body
$\overrightarrow{a}=$  acceleration of a point with respect to ground  
Match the conditions given in column-I with points given in column-II that obey the given condition at the instant shown.

	COLUMN -I		COLUMN-II
a	$\overrightarrow{r}.\overrightarrow{a}=0$	p	P
b	$\overrightarrow{r}.\overrightarrow{v}=0$	q	Q
c	$\overrightarrow{\omega }.\overrightarrow{r}=0$	r	R
d	$\overrightarrow{\alpha }.\overrightarrow{r}=0$	s	S