What type of orbital is Carbon (C) filling?

You may expect bonds between two atoms which each have n covalent lonic metallic hydrogen

Which supports the idea that birds and butterflies both have wings but they do not have a common ancestor with wings? a. the wings are analogous structures that evolved differently and do not have a similar internal structure. b. the wings are homologous structures that evolved differently and do not have a similar internal structure. c. wings of birds are vestigial structures, but the wing structures of bats are not vestigial. d. wings of bats are vestigial structures, but the wing structures of birds are not vestigial

This is a characteristic of the elements in the periodic table that shows a pattern. it may increase or decrease across or down the table.