The correct answer is B. Increases.
The number of free electrons and holes in an intrinsic semiconductor increases when the temperature increases. This is because the higher temperature provides more energy to the electrons in the valence band, allowing them to jump into
the conduction band. This creates more free electrons and holes, which can then carry current.Option A is incorrect because
a decrease in temperature would cause the electrons in the valence band to have less energy, making it more difficult for them to jump into the conduction band. This would result in a decrease in the number of free electrons and holes.Option C is incorrect because the number of free electrons and holes is not constant. It increases with increasing temperature and decreases with decreasing temperature.
Option D is incorrect because 0oC is not a special temperature with respect to the number of free electrons and holes. The number of free electrons and holes increases with increasing temperature, regardless of the specific temperature.
Option E is incorrect because the number of free electrons and holes does increase with increasing temperature.