As a tungsten light bulb ages, it gets dimmer due to a lower current in the filament. Which statement below describes a possible cause for this lower current? A. Tungsten evaporates from the filament, decreasing the cross-sectional area, thus decreasing the resistance.
B. Tungsten evaporates from the filament, decreasing the cross-sectional area, thus increasing the resistance.
C. Tungsten expands, increasing the length of the filament, thus decreasing the resistance
D. Tungsten shrinks, decreasing the length of the filament, thus increasing the resistance.