Match the processes with their characteristics:
$\begin{array}{|l|l|l|} \hline & \textbf{Process} & & \textbf{Characteristics} \\ \hline P. & \text{Electrical Discharge Machining} & 1. & \text{No residual stress} \\ \hline Q. & \text{Ultrasonic Machining} &2. & \text{Machining of electrically conductive materials} \\ \hline R. & \text{Chemical Machining} & 3. & \text{Machining of glass} \\ \hline S. & \text{Ion Beam Machining} & 4. & \text{Nano-machining} \\ \hline \end{array}$
- $P-2, Q-3, R-1, S-4$
- $P-3, Q-2, R-1, S-4$
- $P-3, Q-2, R-4, S-1$
- $P-2, Q-4, R-3, S-1$