The Köppen Classification System for Climate Is Widely Used Because___________

The Köppen classification system for climate is widely used because___________ .

A) it is a highly evolved classification system that has been carefully refined and improved over more than a century so that it meets the complex needs of a modern society
B) it is easy to use, and it covers the most populated areas of the earth and the oceans
C) it uses easily obtained data, and the system is relatively clear
D) it is easy to use, and it covers the most affluent parts of the world, including Europe, the U.S. and north Africa
E) it uses easily obtained data and can cover a large area with a single classification