The answer is nihil because via is direct and straightforward but not nihil
A biped is a being that walks on two legs. A quadruped is a being that walks on four legs. As you already know, an ostrich is a bird that walks on two legs (it is a biped). So in order to complete the analogy, you need to choose an animal that walks on four legs. The correct answer is cat.
Snakes have no legs, and humans and kangaroos are bipeds.
They use it to tell clues and what happen next making you feel interesting...
