The correct answer is B. This is a variant of a Comparison problem, in that we are comparing what both these groups of people earn. A changes the meaning with the verb own. C suggests that high school graduates earn university graduates. D suggests that they earn the earnings of university graduates, and also has the ungrammatical university graduate's earnings. E also suggests that high school graduates are earning university graduates, and also uses the incorrect amount of university graduates rather than number of university graduates.
"Start By Doing What Is Necessary ,Then What Is Possible & Suddenly You Will Realise That You Are Doing The Impossible"