Two resistance of `400 Omega` and `800 Omega` are connected in series with 6 volt battery of negligible internal resistance. A voltmeter of resistance `10,000 Omega` is used to measure the potential difference across `400 Omega`. The error in measurement of potential difference in volts approximatley is
A. `0.01`
B. `0.02`
C. `0.03`
D. `0.05`