Accommodation is: reduction of excitability with rapidly increasing intensity of the stimulus complete non -excitability reduction of excitability with a slowly increasing strength of the stimulus increased excitability with a slowly increasing strength of the stimulus

The correct answer is: complete non-excitability.<br /><br />Accommodation refers to the phenomenon where a neuron or muscle cell becomes completely non-excitable in response to a sustained stimulus. This means that the cell does not respond to further stimulation, even if the stimulus strength increases. This is in contrast to the other options, which describe different types of responses to stimuli.