Which one of the following is a matching pair of a body

Which one of the following is a matching pair of a body feature and the animal possessing it?

1. Ventral central - Leech nervous system
2. Pharyngeal gill slits - Chameleon absent in embryo
3. Ventral heart - Scorpion
4. Post-end tail - Octopus

Leech has ventral central nervous system which consists of nerve ring, and a solid, double, mid ventral nerve cord with ganglia.