单项选择题

From the passage, we can know that ______.

A.20-25% of earth's 6 billion people can use American English
B.20-25% of earth' s 6 billion people can use Dr. Johnson' s English
C.20-25% of earth's 6 billion people can use standard English
D.20-25% of earth's 6 billion people can use English though not idiomatic