This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: miscellaneous, Subject name: Pathology
[{'content': 'A 50-year-old male presented with signs and symptoms of restrictive hea disease. A right ventricular endomyocardial biopsy revealed deposition of extracellular eosinophilic hyaline material. On transmission electron microscopy, this material is most likely to reveal the presence of \nSelect and explain. \nA. Non branching filaments of 7.5 to 10 nm, B. Cross banded fibres with 67 m periodicity, C. Weber Palade bodies, D. Concentric whorls of lamellar structures', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Amyloidosis is the major cause of restrictive cardiomyopathyCardiac amyloid is classically suspected from thickened ventricular walls with an ECG that shows low voltage.By electron microscopy, all types of amyloid consist of continuous, nonbranching fibrils with a diameter of approximately 7.5 to 10 nm. X-ray crystallography and infrared spectroscopy demonstrate a characteristic cross-b-pleated sheet conformationHarrison 19e pg: 1567', 'role': 'assistant'}]