Students applying for hostel rooms are allotted rooms in order of seniority. Students already staying in a room will move if they get a room in their preferred list. Preferences of lower ranked applicants are ignored during allocation.

Given the data below, which room will Ajit stay in ?

$$\begin{array}{l|l}\hline \textbf{Names} & \textbf{Student seniority} & \textbf{Current room} & \textbf{Room preference list} \\\hline \text{Amar} & \text{1}& \text{P} & \text{R,S,Q}\\\hline \text{Akbar} & \text{2}& \text{None} & \text{R,S}\\\hline \text{Anthony} & \text{3}& \text{Q} & \text{P}\\\hline \text{Ajit} & \text{4}& \text{S} & \text{Q,P,R}\\\hline \end{array}$$

- $P$
- $Q$
- $R$
- $S$