The distinguishing characteristic between birds and all other organisms is

the possession of feathers

Explanation:birds are warm blooded animals , that possess feathers.these feathers cover their bodies and used for flight and warmth.their forelimbs are modified into wings,which fold into a Z shape at rest.feathers grow from the skin follicles and are replaced by scales on their legs.they possess oil gland to dress the feathers.

Other features of birds include

1) beaks with no teeth

2) fully ossified bones with air cavities

3)females with left ovary and oviducts only

the answer is golgi apparatus

i would go with b

cytokinesis occurs after telophase so that eliminates d

and the entire reason for cytokinesis is for cellular reproduction