The answer is Emile Durkheim.
Auguste Comte is known as the father of sociology and is famous for his theory of positivism. He did not specifically focus on the study of suicides.
Max Weber was a prominent sociologist known for his work on the sociology of religion, the development of capitalism, and the concept of the "Protestant Ethic." He did not focus on suicides in his studies.
Emile Durkheim is renowned for his sociological study on suicides. His work, "Le Suicide" (1897), is one of the first major sociological studies to use statistical methods to examine social phenomena. Durkheim explored the social factors that contribute to suicide, categorizing it into types such as egoistic, altruistic, anomic, and fatalistic suicides.
Karl Marx is best known for his theories on capitalism, class struggle, and his influence on the development of socialist and communist ideologies. He did not conduct studies on suicides.