A $0-1$ Ampere moving iron ammeter has an internal resistance of $50 \: m \Omega$ and inductance of $0.1 \: mH$. A shunt coil is connected to extend its range to $0-10$ Ampere for all operating frequencies. The time constant in milliseconds and resistance in $m \Omega$ of the shunt coil respectively are
- $2, \: 5.55$
- $2, \: 1$
- $2.18, \: 0.55$
- $11.1, \: 2$