Read the given statements and select the correct option.
(i)Synaptic cleft of neurons secreates adrenaline.
(ii)Myelinated nerve fibres are enveloped with Schwann cells, which form a myelin sheath around the axon.
(iii)Non-myelinated nerve fibre is enclosed by a Schwann cell that does not form a myelin sheath.
(iv)Spinal and cranial nerves are made of non-myelinated nerve fibres.
A. I, II are correct, but III and IV are incorrect
B. I, II and III are correct but IV is incorrect
C. III and IV are correct, but I and II are incorrect
D. II and III are correct, but I and IV are incorrect
