Match the following

$$\begin{array}{|cl|cl|}\hline &\text{Heat treatment process} && \text{Effect}\\ \hline P:& \text{Tempering} & 1.&\text{Strengthening} \\ \hline Q:& \text{Quenching} & 2.&\text{Toughening} \\ \hline R:& \text{Annealing} & 3.&\text{Hardening} \\ \hline S:& \text{Normalizing} & 4.&\text{Softening} \\ \hline \end{array}$$

1. $P-2,\:Q-3,\:R-4\:,S-1$
2. $P-1,\:Q-1,\:R-3\:,S-2$
3. $P-3,\:Q-3,\:R-1\:,S-3$
4. $P-4,\:Q-3,\:R-2\:,S-1$