An ammeter gives full deflection when a current of `2 amp`. Flows through it. The resistance of ammeter is `12 ohms`. If the same ammeter is to be used for measuring a maximum current of `5 amp`, then the ammeter must be connected with a resistance of
A. 8 ohms in series
B. 18 ohms in series
C. 8 ohms in parallel
D. 18 ohms in parallel