This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cell Membrane and transpo protiens, Subject name: Physiology
[{'content': 'The cell membrane consists of various components, including integral proteins. These integral proteins \nSelect and explain. \nA. Are not attached to the outer leaflet, B. Are not attached to the inner leaflet, C. Include transmembrane proteins, D. Are preferentially attached to the surface', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The membrane proteins are classified into two categories: Integral proteins or intrinsic membrane proteins Peripheral proteins or extrinsic membrane proteins. Integral proteins are not only closely associated with the lipid bilayer but also tightly bound to the cell membrane.', 'role': 'assistant'}]