Which of the following represents the correct level of organization for the given organisms?

• A
  Cellular level $\rightarrow$ Hydra,Tissue level $\rightarrow$ Liver fluke,Organ level $\rightarrow$ Leucosolenia,Organ-system level $\rightarrow$ Spongilla
• B
  Cellular level $\rightarrow$ Spongilla,Tissue level $\rightarrow$ Corals,Organ level $\rightarrow$ Nereis,Organ-system level $\rightarrow$ Ascaris
• C
  Cellular level $\rightarrow$ Hyalonema,Tissue level $\rightarrow$ Sea anemone,Organ level $\rightarrow$ Flatworm,Organ-system level $\rightarrow$ Scorpion
• D
  Cellular level $\rightarrow$ Corals,Tissue level $\rightarrow$ Nereis,Organ level $\rightarrow$ Hyalonema,Organ-system level $\rightarrow$ Flatworm