The statements given below highlight some of the chordates features. 

I) They have a hollow nervous system which is present ventrally above the notochord

II) They posses four pharyngeal gill slits present in the form of perforations on the lateral sides of pharynx

III) Epidermis is made up of stratified epithelium

IV) They have two pairs of appendages, one pair at the beginning of the trunk and other in the middle of the trunk

V) They have a closed vascular system.

Which of the above are correct ?