Answer:
The correct answer will be option-C
Step-by-step explanation:
Exercise machines are now widely used to train muscles either in gyms or at home as they are easy and safer to use.
The exercise machines cannot be used without taking training from the experts as using the machine in the correct way requires the expert skills.
The user must be aware of the concept of how the machine helps the exercise training as well as the movement of the body parts one must make while using the machine.
Thus, Option-C is the correct answer.