A.Myasthenia gravis - a chronic autoimmune neuromuscular disease that causes weakness in the skeletal muscles, which are responsible for breathing and moving parts of the body, including the arms and legs.
B.Rheumatoid arthritis - is a long-term autoimmune disorder that primarily affects joints. It typically results in warm, swollen, and painful joints. Pain and stiffness often worsen following rest.
C.Parkinson’s disease - affects the nerve cells in the brain that produce dopamine. its symptoms include muscle rigidity, tremors, and changes in speech and gait.
D.Hay fever - is an allergic reaction to environmental allergens such as pollens, dust mite, moulds and animal hair. Avoiding allergic triggers and taking appropriate treatments are the best ways to reduce the frequency of hay fever symptoms.
So, the correct option is ‘Parkinson’s disease’.