The correct answer is D) It will decrease, causing an increase in the total load current. When additional parallel circuits are added to a circuit, the total circuit resistance decreases. This is because the overall resistance of parallel circuits is always less than the resistance of the individual circuits. As the total resistance decreases, the total load current increases according to Ohm's law (I = V/R). The line voltage remains constant, but the total load current rises due to the reduction in overall circuit resistance. The other options are incorrect because: A) Decreasing resistance would increase the line voltage, not decrease it. B) Decreasing resistance would increase the line voltage, not decrease it. C) Decreasing resistance would increase the total load current, not cause a drop.