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: Physiology
[{'content': 'True about second messengers ? \nSelect and explain. \nA. Act on intracellular receptors, B. Mediate response of extracellular hormones and neurotransmitter, C. Mediate response of intracellular hormones, D. Act by stimulation of transcription', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Mediate response of extracellular hormones and neurotransmitter", 'role': 'assistant'}]