Depends if that's all you're eating... Assuming the amount of oatmeal is 1/2 cup (since that's a serving and it is comparable to 2 apples in calories) you will get less carbs with the oatmeal but more protein. If I had to pick between the two, I'd probably take a whole cup of oatmeal instead of the two apples.
Rough comparison of calories, carbs, fat and protein:
Oatmeal (0.5 cup)
kcal: 140
C: 26
F: 3
P: 5
Apple (x2)
kcal: 162
C: 42
F: 0
P: 0