- A Nephridia
- B Statocysts
- C Malpighian tubules
- D Ommatidia
Correct answer: D. Ommatidia
Explanation: Each compound eye in the cockroach is composed of many individual visual units called ommatidia, each capable of detecting light independently.
Concept context
The four basic animal tissue types (epithelial, connective, muscular, neural) and the cockroach as a model organism for organ-system level organisation.