In multiple sclerosis, identify the part of a neuron that typically hardens and disrupts the flow of information through neurons. the nucleus the dendrites the cell body the myelin sheath

Multiple sclerosis is a condition where the myelin sheath hardens; disrupts the flow of information through the neurons. Myelin sheath is a layer of fatty cells which helps in the transmission of nerves impulses along the axon by insulating it.  It is an outgrowth of a type of glial cell which is formed by a process called myelination or myelinogenesis.
Therefore, the correct answer is Myelin sheath.

Ais your right answer