Old classification systems based on physical characteristics would most likely disagree with the relationship between which two animals in the tree?

1. crocodiles and insects

2. bats and humans

3. birds and bats

4. humans and crocodiles

It's C

The correct option is 3) birds and bats

Explanation:

The functions of the wings of a bat and bird are similar. But the wings of a bird and bat are not similar based on their physical characteristics. Hence, by old classification system, these organisms would not be similar to one another.

The bats have a webbed like structure whereas the birds have a feather like structure. Hence, the correct option is bats and birds.