The right answer is A ! :)
3 squares = 4 circles, so (number of squares)/(number of circles) = 3/4.
3/4 = 12/16
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4 squares = 2 circles, so (number of squares)/(number of circles) = 4/2.
4/2 = 2/1
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2 squares = 5 circles, so (number of squares)/(number of circles) = 2/5.
2/5 = 4/10