PT 8 S1 Q16

Although all birds have feathers and all birds have wings, some birds do ... ...

Which one of the following is most parallel in its reasoning to the argument above?
(A) Ancient philosophers tried to explain not how the world functions but why it functions. In contrast, most contemporary biologists seek comprehensive theories of how organisms function, but many refuse to speculate about purpose.
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in Practice Set: "Parallel Structure" Questions, Set 2