Task: Property Constraint Reasoning (ontology: Earth_Environment/EnvironmentOntology)

The property 'attached to part of' applies to instances of 'anatomical structure', and 'mesoderm-derived structure' is a subclass of 'anatomical structure'. Which class can appear as the value of 'attached to part of' for instances of 'mesoderm-derived structure'?

A. fluid layer
B. algal bloom process phase
C. anatomical structure
D. foamy environmental material

Answer: anatomical structure