The all-or-none principle states that: All stimuli will produce identical action potentials B) all stimuli great enough to bring the membrane to threshold will produce identical action potentials C) the greater the magnitude of the stimuli, the greater the intensity of the action potential D) only sensory stimuli can activate action potentials E) only motor stimuli can activate action potentials

The all-or-none principle is a fundamental concept in neurophysiology that describes how action potentials are generated in neurons. Let's analyze the options provided: A) All stimuli will produce identical action potentials. - This statement is partially true but lacks the critical aspect of the threshold. Not all stimuli will produce action potentials; only those that reach a certain threshold will. B) All stimuli great enough to bring the membrane to threshold will produce identical action potentials. - This statement accurately reflects the all-or-none principle. Once the threshold is reached, the action potential will be of the same magnitude and shape, regardless of the strength of the stimulus. C) The greater the magnitude of the stimuli, the greater the intensity of the action potential. - This statement is incorrect. The all-or-none principle states that action potentials are all the same size once the threshold is reached, regardless of the stimulus magnitude. D) Only sensory stimuli can activate action potentials. - This statement is incorrect. Both sensory and motor stimuli can activate action potentials. E) Only motor stimuli can activate action potentials. - This statement is also incorrect for the same reason as option D. Based on this analysis, the correct answer is: **B) all stimuli great enough to bring the membrane to threshold will produce identical action potentials.**