If natural resources such as food, water, and space are limited, then all organisms face a constant struggle for survival. So, the correct option is B.
What are Natural resources?
A natural resource is something that is found in nature and can be used by people. Earth's natural resources include light, air, water, plants, animals, and soil.
When natural resources are limited in amount, the existing organisms face a constant struggle for survival as they suffer from intra-specific as well as interspecific competition. And due to this, it is required to develop favorable variations in order to survive in such limited resources.
Therefore, if natural resources such as food, water, and space are limited, then all organisms face a constant struggle for survival.
To learn more about Natural resources, refer to the link:
https://brainly.com/question/24514288
