The correct options are
B Pharyngeal gill-slits or lungs are present for respiration.
D A hollow nerve cord is present on the dorsal side.
Depending upon presence or absence of the notochord, the animal kingdom has been divided into two groups- Non-chordates and Chordates. The defining characteristics of a chordate are:
1. The presence of notochord
2. Pharyngeal gill-slits or lungs present for respiration.
3. A hollow nerve cord present on dorsal side of body.
4. Heart that is present on the ventral side of body.