Difference between hydra, sponge and obelia

Hydra are simple freshwater animals, while Obelia lives in the sea or fresh water

Explanation:

The main difference is that Hydra's body shape is a polyp, while Obelia consist of polyps and medusae in its life cycle

well for one plants are always the producer, so a is the answer. a wolf is more of the consumer(predator) and the deer is the prey so i know those two are out of the question. also mushrooms are fungi/fungus so a is the producer.

answer; microsoft;