The correct option is B 15V
Answer is B.
Components connected in parallel are connected so the same voltage is applied to each component. In a parallel circuit, the voltage across each of the components is the same, and the total current is the sum of the currents through each component. In this case, it is a parallel, the voltage across each component will remain the same as 15 V.
Hence, the potential drop across the 6 ohms resistor is 15 V.