I thin it is option d= cortisone

Cortisone does not work as a neurotransmitter but the others are act as a neurotransmitter.  

Explanation:

Cortisone is a type of steroid that prevents the production of those substances which are responsible the cause of the inflammation in the body. Cortisone is used for the treatment of the various diseases like allergic disorders, arthritis, skin problems etc.

This is a anti-inflammatory drug which works by preventing the production of the collagen in the body.