Answer:
(a) bat wing and human hand
Explanation:
The homologous structures are structures at living organisms that are the same, very similar, or have the same function, despite the organisms having different appearance. This can mostly be seen in the bones of the animals, and this type of structures more often then not suggest a distant common ancestor between the species. Usually the homologous structures appear among animals from the same class, so it can be expected that animals from the mammalia class can have these structures, or animals from the reptilia etc. In this case we have the bat wing and the human hand. Both have similar bone structure, and the function of the bones in the bat wing and the human hand is also similar. Both of them are in the class of mammalia, and they do share a very distant common ancestor in the small shrew-like mammals during the reign of the dinosaurs.
