An 84-year-old man is a resident of a nursing home with 2-year history of repetitiveness, memory loss, and executive function loss. dies from pneumonia. A cross section of his brain (below) and a normal brain(above) is shown. Which of the following is most likely?

Above features suggests Alzheimers disease. In Alzheimer's disease, as neurons are injured and die throughout the brain, connections between networks of neurons may break down, and many brain regions begin to shrink. By the final stages of Alzheimer's, this process--called brain atrophy--is widespread, causing significant loss of brain volume Reference: Robbins & Cotran Pathologic Basis of Disease, 9e, Page no. 36