(A) is the inappropriate setup.

In figure B the electric cell is connected to two bulbs and both bulb will consume the cell at very high rate but we are getting more light if we connect two bulb.

In figure C the cell is connected to a bulb which will consume less electricity than the two bulb and it will also give us light.

In figure D the cell is connected to a bulb using a switch which is the most appropriate way to connect bulb, it will use the electric cell at very low rate.

In all these cases we have seen that if cell is getting used up we are getting output in form of light. There is no wastage of energy in these three cases, but in the figure A, positive terminal of the cell are connected to negative terminal of the cell. We are not using current it is just flowing through the wire. And after some time the whole chemical will get consumed up and we will get nothing in return, hence that is why figure A is wrong.