Oxygen in coelenterates is supplied to different tissues by

The correct option is Diffuses through integuments.

Coelenterates (also known as Cnidarians), such as jellyfish, sea anemones, and hydras, are primitive multicellular aquatic animals. They possess a simple tissue-level organization and lack complex organ systems, including dedicated respiratory and circulatory systems.

Because they lack blood, plasma, blood pigments (like hemoglobin), or specialized breathing structures like tracheal tubes (which are found in insects), they rely on direct physical exchange with their aquatic environment.

Oxygen dissolved in the surrounding water enters the body by diffusing directly through the body wall or skin (integuments) and the lining of the gastrovascular cavity. Since their body wall is extremely thin—consisting of only two primary cell layers (ectoderm and endoderm) separated by a gelatinous mesoglea—every cell is in close proximity to the water, allowing simple diffusion to efficiently supply oxygen to all tissues.