Which is a common disease that involves the muscles of the human body?

common primary diseases of the muscular system include inflammatory myopathies, such as polymyositis and dermatomyositis, muscular dystrophy, myasthenia gravis, amyotrophic lateral sclerosis, rhabdomyolysis, and cardiomyopathy, among others.

: Inflamatory myopathies

and the most common one is duchenne muscular dystophy

answer; i do believe that the correct answer is (b)