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

The correct answer is: reduction of excitability with a slowly increasing strength of the stimulus.<br /><br />Accommodation refers to the process by which neurons reduce their excitability in response to a stimulus that gradually increases in strength. This allows the neuron to maintain a stable firing rate despite changes in the stimulus intensity.