Which of the following advances in healthcare occurred during the second half of the 20th century?

The correct answer encompasses a range of significant medical advancements that occurred during the second half of the 20th century. Each of the advances mentioned contributed substantially to healthcare improvements.

The introduction of tranquilizers such as Librium and Valium occurred during this time, marking a significant evolution in the treatment of anxiety and related disorders. These medications helped to transform mental health treatment by offering patients new options with distinct mechanisms of action compared to previous therapies.

The birth control pill, which became available in the 1960s, revolutionized family planning and women's healthcare. It provided women with greater control over their reproductive health and played a crucial role in women's rights movements by allowing for more autonomy during a transformative period in society.

Additionally, the development of the Sabin and Salk vaccines for poliomyelitis represented major public health milestones. These vaccines not only offered effective prevention against a debilitating disease but also led to efforts that ultimately eradicated polio in many parts of the world.

Thus, each of these advancements represents a landmark change in healthcare during that era, collectively contributing to a significant transformation in medical practice, public health standards, and patient options.