USA is the country in which the metric system is not followed. Hence option A will be the correct answer.
All the other countries uses metric system for their units. Due to this season there is no confusion in conversion of the units. But England has special case, its distance is measured in miles and the speed is measured in miles per hour.
The other units are measured in metric uniform. Other than USA there are two more countries which do not accepts the metric unit system they are Liberia and Burma.