Match all items in Group 1 with correct options from those given in Group 2: \[ \begin{array}{|c|c|} \hline \textbf{Group 1} & \textbf{Group 2} \\ \hline P. \text{ Intermediate representation} & 1. \text{ Activation records} \\ \hline Q. \text{ Top-down parsing} & 2. \text{ Code generation} \\ \hline R. \text{ Runtime environments} & 3. \text{ Leftmost derivation} \\ \hline S. \text{ Register Allocation} & 4. \text{ Graph colouring} \\ \hline \end{array} \]