The correct option is B all the cells should be joined in parallel
Let emf of each cell =ε and internal resistance =r
When all cell is joined in series: net resistance rt=Nr and total emf εt=Nε
thus,current , IS=εtrt=NεNr=εr
When all cell is joined in parallel: net resistance rt=r/N and total emf εt=ε
thus,current , IP=εtrt=εr/N=Nεr
Thus current IP is maximum.