Death of tissue associated with a loss of blood supply is:

Ischemia is the critical restriction of blood flow to tissues, resulting in a deficit of oxygen and nutrients necessary for cellular metabolism. If the perfusion pressure remains insufficient for a prolonged period, irreversible cellular injury occurs, leading to necrosis. This pathological process can be complicated by bacterial putrefaction or remain relatively sterile, depending on the environment and the speed at which the vascular supply was compromised. Rationale: A. Gangrene is the medical term for the death of body tissue caused by a lack of blood flow or a serious bacterial infection. It typically affects the extremities or internal organs and is classified as "dry," "wet," or "gas" gangrene. The primary physiological driver is tissue ischemia, which leads to cellular necrosis and the eventual decomposition of the affected anatomical structure. B. An abscess is a localized collection of pus that has built up within the tissue of the body. It is typically the result of an inflammatory response to a pyogenic bacterial infection rather than a primary loss of blood supply. While tissue damage occurs within an abscess, the defining feature is the accumulation of white blood cells and necrotic debris in a contained cavity. C. Eczema is a chronic inflammatory skin condition characterized by pruritus, erythema, and vesicular lesions. It is an immune-mediated or atopic response often related to barrier dysfunction or environmental triggers. It does not involve the death of deep tissue or a significant loss of macrovascular blood supply, making it an incorrect classification for necrotic tissue death. D. A furuncle, commonly known as a boil, is a deep-seated infection of a hair follicle, usually caused by the bacterium Staphylococcus aureus. It manifests as a painful, swollen area with a core of pus and inflammation. Like an abscess, it is primarily infectious and inflammatory in nature, rather than a result of systemic or localized vascular occlusion leading to tissue death.