Architectural Conservator: Several municipal heritage boards require owners of historic limestone buildings to apply synthetic water-repellent sealants, reasoning that preventing moisture penetration protects the facades. However, this requirement is counterproductive. Although synthetic sealants prevent liquid rainwater from entering from the outside, they inevitably seal in ambient moisture migrating from the building's interior. Consequently, during sub-zero temperatures, the trapped moisture freezes and expands beneath the masonry surface, causing irreversible spalling and surface fracturing. For this reason, municipal heritage boards should rescind the mandatory sealant requirement.
Which of the following most accurately describes the role played in the argument by the claim that during sub-zero temperatures, trapped moisture freezes and expands beneath the masonry surface, causing irreversible spalling and surface fracturing?
- AIt is the overall conclusion of the argument that the author's evidence is primarily organized to establish.
- BIt is a background rationale cited to explain why municipal heritage boards initially instituted the sealant mandate.
- It is a subsidiary conclusion supported by an earlier premise and used to support the author's final recommendation.Cevap
- DIt is a concession made to acknowledge a potential drawback of the author's proposed policy change.
- EIt is an unevidenced premise introduced solely to illustrate how liquid rainwater enters porous stone facades.