I don't know if their is sopposed to be options but my best educated guess is "Natural"
The movement of the ocean's crust
The situation is an exponential growth wherein an example is on population when as the population gets larger, it grows more quickly.
Answer;
-Reduce the chance of errors in correspondence
-Easier to use for converting between units while measuring
-Make communication easier between scientists comparing data
Explanation;
-The metric system is a system that is based on joining one of a series of prefixes, including kilo-, hecto-, deka-, deci-, centi-, and milli-, with a base unit of measurement, such as meter, liter, or gram.
-Since the metric system is a decimal system of weights and measures it is easy to convert between units simply by multiplying or dividing by 10, 100, 1000, etc.
-It is an alternative system of measurement used in most countries, as well as in the United States.