The question refers to a circuit diagram ("In the given figure..."), but the figure itself is not provided here. Since the value of $I_1$ depends entirely on the diode orientations and the circuit connections, it is not possible to derive the current uniquely without the diagram.

However, the stored correct answer is C: $2\,\text{A}$. Since no circuit figure is available to verify independently, I cannot rigorously recompute it from first principles.

What would be needed to solve it

To solve such a problem step-by-step, we would normally:

1. Identify which diodes are forward biased and which are reverse biased from the polarity in the figure.
2. Replace each forward biased diode by its given resistance $30\,\Omega$.
3. Replace each reverse biased diode by an open circuit (infinite resistance).
4. Reduce the resulting resistor network using series/parallel combinations.
5. Apply Ohm's law / Kirchhoff's laws to calculate $I_1$.

Because the actual figure is missing, these steps cannot be carried out numerically.

Conclusion

Based on the stored answer, the answer is taken as:

$I_1 = 2\,\text{A}$