Those are really wacky answers to choose from. It isn't B.They are usually man made. It's not C. we still need to be careful. It is not D. It is always your responsibility for whatever you do. It shouldn't be A, but that would kind of make sense. I would choose A.
Answer:
Yes it can.......?????????
Finding out if an exercise is safe needs to determine the fitness level of the exercise and how much it takes to achieve the result of the exercise. The person performing the exercise needs to know their endurance level and if they are able to perform the exercise without injury or illness.