<h2>The speed of action potential propagation get slower down</h2>
Explanation:
Myelination is the process of generating myelin in neurons. In CNS, oligodendrocyte make the myelin sheath.
The main function of myelin is to increase the speed of electrical impulses along the myelinated fiber.
Myelinated fibers lack voltage-gated sodium channels along the myelinated internodes, having them only at the nodes of Ranvier though which the molecules moves.
Demyelination is the loss of the myelin sheath, result due to some neurodegenerative autoimmune diseases, resulting in the decrease of the speed of action potential propagation.
Among the given choices, the only positive effect that may be thought off with the increase in level of CO2 in the atmosphere is the increase of plant growth. Carbon dioxide is an essential compound in the photosynthesis of plants. Therefore, the answer should be letter C.
