Answer:
I think this would be walking on a balance beam.
Step-by-step explanation:
This is because my text says that when you have an underdeveloped Cerebellum, (like in babies), you have trouble with things like coordination, balance, and smooth movements. Without a cerebellum, it would be hard to do those, making balancing on a beam the hardest.
I hope this helps! Have a purrrfect day!! :3