An e.m.f. cell of $4.0\,\text{V}$, with negligible internal resistance, is linked to a fixed resistor of resistance $1.0\,\Omega$ and a potentiometer with maximum resistance $3.0\,\Omega$, as shown. What range of potential differences is available between terminals X and Y?
- A$0\,\text{V}$ to $3.0\,\text{V}$
- B$0\,\text{V}$ to $4.0\,\text{V}$
- C$1.0\,\text{V}$ to $3.0\,\text{V}$
- D$1.0\,\text{V}$ to $4.0\,\text{V}$