Which ONE of the following is not a useful effect of acute inflammation?

The answer is E. Tissue swelling may result in obstruction of a vital passageway, i.e., larynx, or may cause ischaemic necrosis within an enclosed space, i.e., testis.

The others are all useful but some people may have an inappropriate immune response and may therefore develop a pathological condition as part of their physiological response, i.e., asthmatics. There is also a rare condition in which a deficiency of a complement activation controlling factor (C1-inhibitor) allows complement activation to occur (angioneurotic oedema).