Answer: Homologous Structure.
Explanation: Homologous structures can be defined as the structures that are are similar in the structure but the function is different.
These organisms are related because they have show some common ancestor. Same structure performing different functions.
Example: The bones of whale and the and the bones of human have similar structure but their functions vary. The bones of whales function as fins and helps in swimming and the hands of human being is used for holding things.