The floating exchange rate implies that the BoP balances out to zero.
Using the formulas Y = C + S + T and Y (aggregate demand) = C + I + G + (X - M), you can find the value of (X-M) (net exports) and use this to infer what is happening in the economy.
Y = C + I + G + (X - M) ...... (1)
Y = C + S + T ...... (2)
(1) - (2): 0 = (I + G) + (X - M) - (S + T) -> (X - M) = (S + T) - (I + G).
For year one, this means X - M = -15. i.e. the BOGS is negative. Since there is no information on NPY or NSY and we know that the BOGS makes up most of the CA, we can infer that the KAFA is +15.
If you do the same math on Q13, you'll find that X - M = 0, which represents an improvement by $15 on the CA. Answers A and D only changed by $5 and C is wrong (FA decreases), thus the answer is B.