In the circuit diagram shown, contact can be made at any position along the $3\,\Omega$ resistor (potentiometer). The battery has e.m.f. $9\,\text{V}$ and negligible internal resistance. What is the greatest possible range of the output voltage?
- A$0\text{-}2\,\text{V}$
- B$0\text{-}5\,\text{V}$
- C$2\text{-}3\,\text{V}$
- D$2\text{-}5\,\text{V}$