You must know that the formula for getting the circumferance is circumferance=pi times diameter, so in your problem it would be 62.8 = 3.14x (x is the variable standing for the diameter) so then you divide 62.8 by 3.14 either with long division or by using a calculator and you get 20
The answer to your question is A. 62.8 meters.
Hope that this helps, have a great day, chao!!