As the electric current in a lightbulb is slowly increased, the filament glows more and more brightly. why does this happen?

Explanation:

As the current in a light bulb increases gradually, the filament shines more and more brightly. This occurs as the more current passes through a light bulb, the brighter it glows.  

The more the current, the more will be the power, here the power determines the brightness of a bulb. More the current, the more will be the dissipation of power in the form of light and heat. If the current enhances then the brightness will also get an increase.  

answer; ///i do believe that the correct answer is (b); ///particle composed of two or more atoms bonded together;