Which of the following character is not found in all the chordates:

1. Diaphragm

2. Coelom

3. Pharyngeal gill clifts

4. Dorsal nerve cord

In which of the following animal post-anal tail is found:
1.  Earthworm
2.  Lower invertebrate
3.  Scorpion
4.  Snake

In which of the following, the notochord is present in the embryonic stage?