Which of the following statemetn are correct and incorret
1. Synaptic cleft of neurons secrate adrenaline
2. Myelinated nerve fibres are enveloped with Schwann cells, which form a myelin sheath around the axon
3. Non- myrlineated nerve fibre is emclosed by a schwann cell that from a myelin sheath.
4. Spinal cord and cranial nerve are made of non-myelinated nerve fibres of the four statemets
A. 1,2 are correct but 3 and 4 are incorrect
B. 1,2 and 3 are correct but 4 is incorrect
C. 3 and 4 are correct but 1 and 2 are incorrect
D. 1 and 4 correct while 2 and 3 are incorrect
