Brain Test Level 98 Answer
Rocking the baby or reaching for a bottle, the two things a crying baby usually wants. The question already names the problem, and it is not hunger or tiredness.
The puzzle
The baby is crying because she is gassy.
The answer
Rub the baby's belly gently with your finger for a few seconds until she burps and smiles.
What most people try first
Rocking the baby or reaching for a bottle, the two things a crying baby usually wants.
Why that is the answer
The question already names the problem, and it is not hunger or tiredness. It says she is gassy, so the fix has to act on her stomach rather than on her mood. Rub her belly gently with a finger and hold it there for a few seconds until she burps. Reading the sentence for the cause instead of the symptom is the skill this level is testing.
If your level 98 looks different
Unico Studio shuffles level numbers between game versions and platforms, so the puzzle on your screen may carry a different number from the one here. If the question above is not the one you are looking at, the full levels 51 to 100 walkthrough lists every puzzle in this stretch by its question, which is easier to match than a number.