Study the following statements and select the true statements about neuron.

i) When a neuron is suitably stimulated, an electrical disturbance is generated.

ii) Arrival of the electrical disturbance at the output zone, triggers events that cause only inhibition of adjacent neurons.

iii) Nissl’s granules are present in efferent fibre of neuron.

iv) Myelin sheath is absent at nodes of Ranvier.