Concept:Levels of organisation of life progress from cells, to tissues, to organs, and then to organ systems.
Explanation:At the organ level of organisation, the body is composed of distinct organs, and each organ performs a specific function.
Euglena is a unicellular organism, so it shows cellular or protoplasmic organisation.
Spirogyra is a filamentous alga, and its similar cells remain grouped in filaments, so it shows cellular organisation.
Ginger is a flowering plant whose body has tissues, organs, and organ systems.
Tapeworm is a flatworm in which tissues are organised into distinct organs, so it is at the organ level of organisation.
Answer:D. Tapeworm