1. BENEFICIAL : producing a favorable result.
2. DERMATOLOGICAL : having to do branch of medicine concerned with the skin.
3. OSTEOARTHRITIC : having a degenerative bone disease.
4. PATHOLOGICAL : relating to or caused by disease.
5. CREDENTIAL : that which entitles one to confidence, credit, or authority.
6. POLYTHEISTIC : pertaining to the belief in more than one God.
Answer A. Innate.
We do not know if it is a trait that all humans are born with (which would be innate), or if it's something that we develop as we grow older.
The other words wouldn't make sense in the place of innate.