Final answer:
The level of organization that includes both biotic and abiotic factors such as snails, phytoplankton, water, and sunlight in a forest is an ecosystem.
The correct answer is option A Ecosystem.
Step-by-step explanation:
The level of organization that includes all of the snails, phytoplankton, water, sunlight, and turtles in a deciduous forest is an ecosystem. An ecosystem consists of all the living things, known as biotic factors, such as snails and turtles, and all of the nonliving, or abiotic, parts of the environment, such as water and sunlight.
Within an ecosystem, these biotic and abiotic components interact and are interconnected. A biome, on the other hand, is a group of similar ecosystems with the same general type of physical environment, and the biosphere is the collection of all ecosystems.
A community is just the living components and would exclude abiotic factors like water and sunlight, while a population includes individuals of a single species in an area.
The correct answer is option A Ecosystem.