The correct answer is option 3 - Eugenics. Eugenics is the branch of science that deals with the improvement of the human race through the control of hereditary traits. It focuses on promoting the reproduction of individuals with desirable traits and discouraging the reproduction of those with undesirable traits. Eugenics aims to enhance the genetic quality of the human population by selectively breeding individuals with superior traits. This concept gained popularity in the early 20th century and was used to justify policies such as forced sterilization and restrictive immigration laws. However, it has been widely criticized for its unethical and discriminatory practices, particularly its association with eugenics programs implemented by the Nazis during World War II. It is important to note that while eugenics may have had negative connotations in the past, contemporary advancements in genetic research and technology are used for ethical purposes such as genetic counseling and reproductive technologies, focusing on improving overall health outcomes rather than promoting a specific set of traits.