At absolute zero temperature a semiconductor behaves like:A. an insulatorB. a superconductorC. a good conductorD. a variable resistor

At absolute zero temperature (0 Kelvin or -273.15 degrees Celsius), a semiconductor behaves like an insulator.

In semiconductors, as the temperature decreases, the energy of electrons in the valence band decreases, and the energy gap (band gap) between the valence band and the conduction band remains relatively large. This large band gap prevents the easy movement of electrons from the valence band to the conduction band, making the material behave like an insulator, with very few electrons able to conduct electricity.

So, the correct answer is A. an insulator.