A rigid link $PQ$ is undergoing plane motion as shown in the figure ($V_P$ and $V_Q$ are non-zero). $V_{QP}$ is the relative velocity of point $Q$ with respect to point $P$.

Which one of the following is TRUE?

1. $V_{QP}$ has components along and perpendicular to $PQ$
2. $V_{QP}$ has only one component directed from $P$ to $Q$
3. $V_{QP}$ has only one component directed from $Q$ to $P$
4. $V_{QP}$ has only one component perpendicular to $PQ$