Answer:
The correct option is A
Step-by-step explanation:
Overloading of muscle is caused by subjecting the muscle to more stress than they are accustomed to. This is the technique used by body builders to build the muscle mass. When the muscle is continuously subjected to this added stress, it eventually adapts to this stress by producing new myofibrils (which makes up the muscle fibre). This added stress causes the muscle fibre to grow bigger and stronger in order to handle this additional stress subsequently.