Which type of cellular adaptation is most likely to occur as the result of chronic ischemia to a region?

The correct answer is atrophy.

Atrophy refers to a complete or partial wasting away of a segment of the body. The causes of atrophy include poor nourishment, mutations, poor circulation, loss of nerve supply to the target organ, loss of hormonal support, an excessive amount of apoptosis of cells, and lack or disuse of exercise, or disease intrinsic to the tissue itself.

Atrophy is the usual physiological procedure of breakdown or reabsorption of tissues, involving apoptosis. When it takes place as a consequence of loss of trophic support due to disease, it is called pathological atrophy.