A dichotomous key is an essential tool when it comes to identifying organisms that are based on the observable traits of the organisms.
The answer to this exercise is Row 1. It is because the wasp has six legs, which is found in the III option- group D. It is also true with the ant which is also belonged to group D. The tiger. In the I, the tiger has no wings obviously that is why it belongs to group A. The bird has wings and it has feathers, so it belongs to group B.