The correct answer is B.
Emil Kraepelin (1856 - 1926) was an influential German psychiatrist who developed a classification system for mental illness. He was the first person to do this. His classification system, which was called the Compendium der Psychiatrie (1883) was instrumental in future classification systems for mental illness. Through his own studies he realized that mental illness could be divided into two types of disorders, those that were affected by external factors and those that had biological causes. He then classified these disorders.
