What organisms in the lake require oxygen to survive?

The correct answer is - producers (plants), consumers (fishes, mollusks and turtle) and decomposers.

Explanation:

In a lake ecosystem, there are many organisms found from microbes like bacteria to fishes and turtles and plants or phytoplankton. Almost all organism requires oxygen to perform their cellular activities and survives.

In lakes, organisms that require oxygen to survive are producers that make their food themselves selves such as plants and phytoplankton. Different level of consumers also requires oxygen such as mollusks, small fishes, turtles, big fishes. Decomposers are also needed oxygen to perform their activity.

Thus, the correct answer is - producers (plants), consumers (fishes, mollusks and turtle) and decomposers.