<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:An autopsy is performed on a 39-year-old man 5 days after he was found pulseless at his apartment by his neighbor. Examination of the brain shows liquefactive necrosis in the distribution of the right middle cerebral artery with surrounding edema. Immunophenotyping of a sample of the affected brain tissue shows numerous cells that express CD40 on their surface. On further histopathological evaluation, the morphology of these cells is not readily discernible with Nissl stain. These histological findings are most consistent with which of the following cell types?? A: Radial glial cells, B: Microglia, C: Astrocytes, D: Oligodendrocytes, E: Neurons,  <response>: This is a question about identifying the cell type most consistent with the histological findings described in a patient with an infarction in the distribution of the right middle cerebral artery. The key findings are liquefactive necrosis and edema in the affected brain tissue, along with cells expressing CD40 that have indistinct morphology on Nissl staining. CD40 is a cell surface receptor expressed on antigen presenting cells like microglia and macrophages. Liquefactive necrosis and edema are typical consequences of ischemic stroke caused by occlusion of a major cerebral artery. Microglia proliferate and become activated in response to brain injury, taking on an indistinct morphology. Therefore, of the cell types listed, activated microglia are most consistent with the histological findings described.B: Microglia 