Final answer:
Sigmund Freud developed the technique of treating emotional problems by exploring the subconscious, a method known as psychoanalysis.
Step-by-step explanation:
The technique of treating emotional problems through the exploration of the subconscious was developed by Sigmund Freud. Freud's method, known as psychoanalysis, includes the analysis of dreams, free association, and the examination of the patient's interaction with the therapist to uncover and resolve unconscious conflicts rooted in childhood experiences. This exploration of the subconscious aimed to address neurotic symptoms and improve mental health.