I1 = 2 Amp
I2 = 1 Amp
D seems to be correct as well.
But I would have picked C because it makes sense right away.
If I have to justify why D isn't the answer, I would say that because current depends on resistance and since we don't know the resistances of R1 and R2 (although we can infer based on currents), the conclusion that "I1 must be greater than I2" doesn't follow.
I hope someone else can take a stab at it.
