25) G

For this question, it is important to ignore the mention of Y chromosome. The question does not tells us whether Y chromosome plays a part in determining the sex of the fruit fly. The only way to determine the sex of a fruit fly is by the ratio of X and A chromosomes. 

XAA:
The ratio (X:A) = 1 : 2 = 0.5 : 1
So the fruit fly will be male


XYAA:
Ratio = 1 : 2 = 0.5 : 1
So the fruit fly will be a male


XXAA:
Ratio = 2 : 2 = 1 : 1
So the fruit fly will be a female


XXYAA:
Ratio = 2 : 2 = 1 : 1
So the fruit fly will be a female


XXYYAA:
Ratio = 2 : 2 = 1 : 1
So the fruit fly will be a female

Hence the answer will be G.