Match the genetic disorder (Column I) with its molecular basis (Column II).
\begin{array}{|c|c|c|}
\hline \text{Column I} & \text{Column II} \\
\hline \text{P. Sickle-cell anemia} & 1. \text{Mutation in nucleotide excision repair} \\
\hline \text{Q. Xeroderma pigmentosum} & 2. \text{Trisomy of chromosome 21} \\
\hline \text{R. Tay-Sachs disease} & 3. \text{Mutation in} ~\beta-\text{globin gene} \\
\hline \text{S. Down Syndrome} & 4. \text{Mutation in hexosaminidase A gene} \\
\hline
\end{array}
- $\text{P-1; Q-4; R-2; S-3}$
- $\text{P-3; Q-4; R-1; S-2}$
- $\text{P-3; Q-1; R-4; S-2}$
- $\text{P-4; Q-2; R-3; S-1}$