What were significant improvements to public health after Lister's work?

The choice highlighting hand washing and carbolic spray usage is correct because these practices were direct results of Joseph Lister's pioneering work in antiseptic techniques. Lister introduced the use of carbolic acid (phenol) as a disinfectant during surgeries, which drastically reduced postoperative infections and improved patient outcomes. Additionally, he emphasized the importance of hand hygiene in preventing the spread of germs, which became a foundational principle in modern medicine. By promoting these practices, Lister significantly advanced public health standards in surgical environments, ultimately leading to safer surgical procedures.

Other options do not accurately reflect improvements connected to Lister's work. Regular patient check-ups and medication monitoring, although vital for healthcare, are not innovations introduced by Lister. Similarly, the claim of reduced surgical procedures in hospitals contradicts the reality that Lister's practices actually made surgery safer and more acceptable, leading to an increase in the frequency of operations. Lastly, while increased patient stays in recovery might be a consequence of improved surgical practices, it is not a direct improvement to public health resulting from Lister’s antiseptic methods.