$Group\; I$ lists spectroscopic methods and $Group\; II$ lists biomolecular applications of these methods. Match the methods in $Group\; I$ with the applications in $Group\; II$.
$$\begin{array}&&\textbf{Group I} & \textbf{Group II} \\ &\text{P. Infrared} & \text{1. Identification of functional groups}\\
&\text{Q. Circular Dichroism} & \text{2. Determonation of secondary structure} \\
&\text{R. Nuclear Magnetic Resonance} & \text{3. Estimation of molecular weight} \\
&\text{} & \text{4. Determination of $3-D$ structure} \\ \end{array}$$
- $P-4, Q-3, R-1$
- $P-2, Q-1, R-3$
- $P-1, Q-2, R-4$
- $P-3, Q-2, R-4$
