A student sets up a variable potential divider (potentiometer) circuit. How does the voltmeter reading change as the sliding contact $T$ is moved from $R$ towards $S$?
- AIt decreases from $12\,\text{V}$ to $0\,\text{V}$.
- BIt increases from $0\,\text{V}$ to $12\,\text{V}$.
- CIt remains at $0\,\text{V}$.
- DIt remains at $12\,\text{V}$.