The correct options are
A Overpopulation
B Lack of rainfall
D Deforestation
Water shortage or water scarcity arises due to lack of water and no fulfillment of the public's demand for water. Due to increase in population, people move to cities which leads to building more shelters, for which people are clearing the forests by cutting down the trees i.e, deforestation. Due to deforestation water cycle gets affected thereby reducing the rainfall, and lack of rainfall is responsible for the shortage of water.