Some species of jellyfish, when injured or stressed, can revert from their adult medusa form to their juvenile polyp stage, effectively beginning life again. Popular accounts have called these animals "immortal," but biologists who study them are careful: the jellyfish can still be eaten, infected, or otherwise killed; what they have escaped is only senescence — the gradual decline that ends most lifespans. Indefinite is not the same as invulnerable.
Which choice best states the main idea of the text?
- Acheck_circle
These jellyfish escape biological aging but remain killable, complicating the popular 'immortal' label.
- B
These jellyfish are truly immortal.
- C
Senescence is unique to vertebrates.
- D
Jellyfish revert to polyps for fun.
Explanation
The passage stakes out a careful position: indefinite lifespan, not invulnerability — C. A is the popular overclaim; B is silly; D is unsupported.