A battery and a resistor are joined in series. The resistor has a value of $20\,\Omega$. The battery’s potential difference (p.d.) is $4.0\,\text{V}$. What current flows through the resistor?
- A$0.20\,\text{A}$
- B$4.0\,\text{A}$
- C$5.0\,\text{A}$
- D$80\,\text{A}$