The Water Model

Things are very similar in an electric circuit with a battery and a transducer, let's say a light bulb. In the beginning the battery's voltage is still high and the light bulb shines brightly. But after a while the battery's voltage decreases and the light bulb can merely shine dimply now. Finally no voltage between the positive and the negative poles is left and the light bulb goes off.

When does the light bulb shine the brightest?

a) The higher the voltage of the battery, the brighter shines the light bulb.

b) The longer the glow wire, the brighter shines the light bulb.