A 68-yr-old woman suddenly lost consciousness; on awakening one hour later , she could not speak or move her right arm and leg. 2 months later ,a head CT scan showed a large cystic area in the left parietal lobe. Which of the following pathological processes has mostly occured in brain? 1. Fat necrosis 2. Coagulative necrosis 3. Liquefactive necrosis 4. karyolysis 5. Apoptosis