B because you multiplies both top and bottom by 3
C because when simplifying the numerator, you get 2a+2b and when simplifying the denominator you get 2a-2b. If you divide both top and bottom by 2, you would get the original ratio.
That's it.
A is wrong because it flipped the top and bottom, D is wrong because it does the same thing as A after being simplified, and E is wrong because 1/3 is not equal to 0.3.
