Chlorophyll is found in which of the following :

Chlorophyll is the green pigment that absorbs light energy and drives photosynthesis. Among the eukaryotic organisms named in this question, chlorophyll occurs only inside the chloroplasts of autotrophic groups — plants, algae, and certain photosynthetic protists of Kingdom Protista.

Euglena is classified in Kingdom Protista precisely because its cells carry chloroplasts packed with chlorophyll — the same pigment plants use — letting it manufacture food in sunlight while also being able to take in food directly when light is unavailable.

Here is how the other three organisms are classified instead:

• Hydra belongs to Phylum Cnidaria, Kingdom Animalia — an animal that obtains nutrition by capturing and digesting prey with stinging tentacles.

• Jellyfish also belongs to Phylum Cnidaria, Kingdom Animalia, feeding the same way: capturing and digesting prey with tentacles.

• Sycon belongs to Phylum Porifera, Kingdom Animalia — a sponge that filters food particles suspended in water.

Since only Kingdom Protista and Kingdom Plantae members carry chloroplasts, and only Euglena among the four options is classified in a chlorophyll-bearing group, the classification test cleanly settles the answer.