Which of the following is one of the cardinal signs of inflammation?

Rubor, which translates to redness, is one of the cardinal signs of inflammation. The cardinal signs of inflammation are a set of clinical indicators that arise due to the body's immune response to injury or infection. These signs typically include redness (rubor), heat (calor), swelling (tumor), pain (dolor), and loss of function (functio laesa).

Increased blood flow to the affected area causes the redness and heat, while the accumulation of fluids results in swelling. Pain is often a result of inflammation that irritates nearby tissues and nerves. This combination of symptoms reflects the body's effort to isolate and eliminate pathogens, facilitate the healing process, and restore function.

Other options such as pallor, necrosis, and fibrosis do not represent the classic signs of inflammation. Pallor refers to paleness, typically indicating reduced blood flow, and is not associated with the inflammatory response. Necrosis is the death of cells or tissue and is a result, rather than a sign, of inflammation. Fibrosis is the formation of excess fibrous connective tissue, which can occur during the healing process but is also not an immediate sign of inflammation.