A man two flats for $675958 each. On one he gains 15% while on the other he loses 15%. How much does he gain or lose in the whole transaction?  Choose the correct choice from the following choices.
A) 2 %  B) 2.25 %  C) 3.12 %  D) 4.65 %  E) 5.12 %

Rationale: "in such a case there is always a loss loss % = ( 15 / 10 ) ^ 2 = 9 / 4 = 2.25 % answer is b"
Answer: B