Which type of drugs kill pain by blocking impulses at specific receptor sites of the brain and spinal cord? narcotic analgesics non-narcotic analgesics anti-psychotics tranquilizers

I believe the correct answer from the choices listed above is the second option. Analgesics are the drugs that kill pain by blocking impulses at specific receptor sites of the brain and spinal cord. Analgesics are drugs that alleviate pain without causing anesthesia. Hope this helps.

The independent variable is the type of music.the dependent variable is the pulse rate.the intervening variable is the age of the subject.if the mother does not like rock, her pulse is likely to not increase.the same might be true for the sister.the friend may like rap and gets excited.to establish cause/effect relationship, all of the subjects must be consistent.hope i .