This question tests the understanding of vocabulary in context, specifically the meaning of 'prolonged'. The correct answer is 'Extended', as it accurately reflects the idea that modern medicine has extended the duration of the physical agony of dying patients. Option A, 'Shortened', is the opposite of the intended meaning. Option C, 'Eliminated', is incorrect because the sentence implies that the agony still exists, just for a longer period. Option D, 'Intensified', might be a distractor as it suggests an increase in severity, not duration.