Given the task definition and input, reply with output. In this task, you are given a multiple-choice question about healthcare. Answer the question based on your information and classify your answers into '1', '2', '3', and '4'.

Question: The neurofibrillary tangles are anomalous structures that are observed in Alzheimer's patients and that consist of:
Options: <1> Neurons in process of extinction by accumulations of intertwined filaments of tau protein that alter the transport of substances in the cytoplasm. <2> Extracellular deposits containing a nucleus of beta-amylase protein surrounded by degenerating axons and dendrites. <3> Proteins that serve to facilitate the production and transport of a cerebral neurotropic factor. <4> Accumulation of astrocytes and microgliocytes with the ability to react to external pathogens. <5> Proteins produced by a defective gene that increases the likelihood of Parkinson's disease.
1