(D) The SI system, which is based on the metric system, has been more widely adopted than the English system, which is harder to use describes the difference between the SI and English systems of measurement.
The SI system has many names in order to cover different ranges of the same measure. These names are made by simply adding prefixes such as "kilo","milli" etc. The units of SI system are: metre, are, litre etc which are widely used due to its ease.