The two factors that ultimately decide what organisms can live in an area are water and oxygen. This is best represented by option 4, or D.
While it may seem that food and water are the most important, we must note that many organisms can make their own food in a process known as photosynthesis. Water and oxygen are fundamental and essential for the majority of biotic factors in that their availability influences what organisms can and can’t thrive in a given environment. Water is often used in most biological processes, and oxygen is required for aerobic cellular respiration to generate energy. While temperature, food, and other environmental conditions play a significant role, water and oxygen are both critical for the survival and prosperity of an organism.