When a galvanometer is shunted with a `4 Omega` resistance, the deflection is reduced to one-fifth. If the galvanometer is further shunted with a `2 Omega` wire, determine current in galvanometer now if initially current in galvanometer is `I_(0)` (given main current remains same).
A. `I_(0)/(13)`
B. `I_(0)/B`
C. `I_(0)/8`
D. `(15I_(0))/(13)`