AIIMS 2017 Biology Classification of Animals MCQ Question

Option A is incorrect because Aurelia aurita, commonly known as the moon jellyfish, belongs to the class Scyphozoa, but the term "jellyfish" is a common name that can refer to multiple classes, including Hydrozoa and Cubozoa. In contrast, options B, C, and D correctly match the organisms with their respective classifications: Chaetopterus is indeed a polychaete worm, Oniscus is a terrestrial isopod within Crustacea, and Balanoglossus is accurately classified under Enteropneusta. This highlights the importance of precise taxonomic classification in biological sciences.