The correct answer for the type of plant that a cactus is referred to as is option 3, Xerophyte. A xerophyte is a plant that is adapted to survive in dry and arid conditions, such as deserts. Cacti have evolved several unique adaptations that allow them to survive in these harsh environments. They have specialized stems that store water, enabling them to withstand long periods of drought. Their leaves are either reduced or modified into spines, which help to reduce water loss through evaporation. Additionally, cacti have a shallow but wide root system that allows them to quickly absorb any available moisture from rain or dew. This combination of adaptations makes cacti well-suited to survive in hot and dry climates.