While muscular strength is the ability of a muscle to exert maximum force against resistance, muscular endurance is the ability of a muscle to exert less than maximum force repeatedly, over a period of time. Thus, endurance is different from strength; it requires the ability to perform a muscular action for a prolonged time period.
Its the Chromosomes, if your talking about the human cells.
They are most mainly consists of "Keratin"
So, option B is your answer.
Hope this helps!
