The answer is A, because you don't want those extremely dangerous chemicals to harm or even kill a living person/pet.
Hope this helps and have a nice day:)
The brain cortex or cerebral cortex is the part of the brain which is responsible for higher thought and function.
Answers.com
C. To provide educational programs to the public
D. To provide immunization programs to diagnose disease.
To provide reliable and sanitary systems of waste removal.
The correct answer of the given question above would be MUCOUS MEMBRANES. The type of membranes lining the body’s orifices and its respiratory, digestive<span>, reproductive, and urinary </span>tracts assists in repelling microorganisms is called the mucous membranes. Hope this answer helps.