Which types of impurity is added to a semiconductor material so that it can provide holes?

Explanation

The correct answer is Trivalent. Trivalent impurities, such as Boron, have three valence electrons. When added to a semiconductor material, they create 'holes' by accepting electrons, leading to the formation of a p-type semiconductor, which is characterized by the presence of holes as majority carriers.Other options are incorrect because tetravalent impurities do not alter the balance of electrons and holes in the semiconductor. Pentavalent impurities add extra electrons rather than creating holes, resulting in an n-type semiconductor. Monovalent impurities are not suitable for semiconductor doping to create holes or electrons.