Match the entries in the $\text{Group I}$ with the elution conditions in $\text{Group II}$.

$\begin{array}{|l|l|l|l|} \hline & \text{Group I} && \text{Group II} \\ \hline P. & \text{Ion-exchange chromatography} & 1. & \text{Isocratic solvent} \\ \hline Q. & \text{Hydrophobic column chromatography} & 2. & \text{Ampholytes} \\ \hline R. & \text{Gel filtration chromatography} & 3. & \text{Increasing gradient of salt} \\ \hline S. & \text{Chromatofocusing} & 4. & \text{Decreasing gradient of polarity} \\ \hline \end{array}$

1. $\text{P-4, Q-1, R-2, S-3}$
2. $\text{P-4, Q-3, R-1, S-2}$
3. $\text{P-3, Q-4, R-1, S-2}$
4. $\text{P-3, Q-4, R-2, S-1}$