This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
[{'content': 'A small Ca+2 binding protein that modifies the activity of many enzymes and other proteins in response to changes of Ca+2 concentration is known as: \nSelect and explain. \nA. Cycline, B. Calmodulin, C. Collagen, D. Kinesin', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]