Calculate the power consumed by the resistor:

Correct option is D

$$P = V \times I \\\\\text{where:} \\V = 4\ \text{V (voltage across the resistor)} \\I = 3\ \text{A (current through the resistor)} \\\\\text{Calculation:} \\P = 4 \times 3 = 12\ \text{W}$$​​