Answer;
B) Neurons, epithelial cells
Explanation;
-Primary lateral sclerosis (PLS) is a rare neuromuscular disease with slowly progressive weakness in voluntary muscle movement. PLS belongs to a group of disorders known as motor neuron diseases. PLS affects the upper motor neurons (also called corticospinal neurons) in the arms, legs, and face.
-It occurs when nerve cells in the motor regions of the cerebral cortex (the thin layer of cells covering the brain which is responsible for most higher level mental functions) gradually degenerate, causing movements to be slow and effortful. The disorder often affects the legs first, followed by the body, trunk, arms and hands, and, finally the bulbar muscles (muscles that control speech, swallowing, and chewing).
