Concept: Similar structure: This is the structure of unrelated creatures that have evolved to perform the same function. 

Analogous structures that have similar forms or functions but weren't present in that group's most recent common ancestor are created via convergent evolution. 

Man's lungs and prawn gills can both show a comparable structure. As a result, the Gills of the Prawn and the Lungs of Man are comparable structures.

Hence, option A is the correct answer.