Which of the following best describes regional anesthesia?

Regional anesthesia is characterized by the loss of sensation in a limited area of the body, which occurs through the targeted application of anesthetic agents near specific sensory nerves. This method allows for effective pain control in a localized region, making it particularly useful for surgeries or procedures involving specific limbs or body parts without affecting the entire system.

The other options describe different anesthesia methods that do not align with the definition of regional anesthesia. For instance, loss of sensation throughout the entire body refers to general anesthesia, which affects the whole system rather than a specific area. Topical application, while it can provide localized anesthesia, is not the same as regional anesthesia, which typically involves injections near nerve pathways. Lastly, performing a procedure under general anesthesia means the patient is completely unconscious and does not experience sensations, contrasting with the targeted approach of regional anesthesia.