The diagram presents a circuit that includes a battery and cells with negligible internal resistance. Several values of current, electromotive force (e.m.f.) and resistance are given. One resistor is marked P. What is the resistance of resistor P?
- A$0.40\,\Omega$
- B$0.80\,\Omega$
- C$2.0\,\Omega$
- D$2.8\,\Omega$