For the potentiometer circuit shown, the ammeter first has a zero reading. Next, the light-dependent resistor (LDR) is covered, causing the ammeter to show a non-zero reading. Which change could bring the ammeter reading back to zero?
- ADecrease the supply voltage.
- BIncrease the supply voltage.
- CMove the sliding contact to the left.
- DMove the sliding contact to the right.