What most likely explains why both species have tentacles and why the tentacles are different?

This sea anemone and this ctenophore both have tentacles, which are body structures that help them catch food. However, sea anemone tentacles are short and can sting, while ctenophore tentacles are long for grabbing and cannot sting. What most likely explains why both species have tentacles and why the tentacles are different?
a
b
c
d