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': 'True statement regarding covalent bonds is \nSelect and explain. \nA. Electrons have same spin, B. Electrons have opposite spin, C. They are weak bonds, D. None of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Covalent bonds are the strongest bonds and are formed by sharing of a pair of electrons between adjacent atoms.\nThe two electrons of pair have opposite spin.', 'role': 'assistant'}]