Which of the following words is written correctly?

The word "anti-inflammatory" is a compound adjective that is correctly hyphenated and widely accepted in medical and general English usage. It describes substances that work against inflammation and has become standardized in both scientific literature and everyday language. The prefix "anti-" is combined with "inflammatory" to clearly communicate the meaning that the substance opposes or counteracts inflammation.

In contrast, the other options present variations that are generally considered incorrect or less common. For instance, "pro-active" is often written as "proactive" in modern usage, dropping the hyphen as it has become a widely recognized single word. Similarly, "un-American" is typically deemed correct, but "re-active" is less frequently used and is more commonly written as "reactive." Therefore, "anti-inflammatory" stands out as the word that is consistently accepted and correct in its hyphenated form.