For the circuit shown, the locus of the impedance $Z (j \omega)$ is plotted as $\omega$ increases from zero to infinity. The values of $R_{1}$ and $R_{2}$ are:
- $R_{1} = 2 \; \text{k} \Omega, R_{2} = 3 \; \text{k} \Omega$
- $R_{1} = 5 \; \text{k} \Omega, R_{2} = 2 \; \text{k} \Omega$
- $R_{1} = 5 \; \text{k} \Omega, R_{2} = 2.5 \; \text{k} \Omega$
- $R_{1} = 2 \; \text{k} \Omega, R_{2} = 5 \; \text{k} \Omega$