Breuer discovered that

a. hysterical symptoms were alleviated after patients discussed them under hypnosis.
b. dogs salivate to a bell if the bell is rung prior to feeding.
c. discussing problems while hypnotized leads to patient insight.
d. general paresis was caused by the same bacteria that cause syphilis.

Answer: a. hysterical symptoms were alleviated after patients discussed them under hypnosis.