Three moving coil galvanometers \[A,{\rm{ }}B\,\,and\,\,C\] are made of coils of three different material having torsional constant $1.8\,\, \times \,\,{10^{ - 8}},\,\,2.8\,\, \times \,\,{10^{ - 8}}$and $3.8\,\, \times \,\,{10^{ - 8}}$ respectively. If the three galvanometers are identical in all other respect, then in which of the above cases sensitivity is maximum?