Answer:
A. the A-not-B error
Explanation:
The A-not-B error can be found in kids that are under 1 year old, and sometimes older, that is caused by a cognositive impossibility on their brains of once they have found the object several times on one spot, they will try and search for it on the same spot where they found it before even if they see the object being hidden in othe spot, this will go away when they get older and start to understand the world differently.