To determine the velocity of an object, you need to know the displacement and the change in time.
v = displacement / change in time
Well not calculus because that has nothing, well mostly nothing to do with balancing chemical equation, so B or C. Now for me personally B is way faster, though C is sometimes faster if you get lucky the way to solve it is B
Explanation:
fractional distillation method is used to obtain petrol from petroleum...
hope it helps
Your answer is b because it is