All of these are first-line defenses except a. saliva c. antibodies b. cilia d. enzymes

All of these are first lines of defense except D. Enzymes. 
Cilia are eyelashes, or little hairs that resemble eyelashes. Saliva is in our mouth to help digest our food and get rid of some stuff. Antibodies help get rid of sicknesses.

I believe that the answer is :
EXCEPT
d) enzymes

We have to remind them that ASL is their language and it does not reflect their intelligence. Language variation in the Deaf World is called register. Register refers to variation in language according to the formality or informality. Intimate, casual, consultative, formal, and frozen.  Some Deaf feel low when they use strong ASL, feeling that they do not have good English.