Aspecific time during development at which a particular event has its greatest consequences and the presence of certain kinds of environmental stimuli is necessary for development to proceed normally is called

The answer is "it is called critical period".

There are critical development periods that are time periods in your kid's development during which she is prepared to learn, ace, or build up another aptitude. The youngster must be prepared, and nature ought to have the capacity to support the acing of the new ability. Some behavioral scientists trust that if a kid isn't helped to take in another aptitude in certain basic periods, she won't learn it all alone and may never learn it and also on the off chance that she had learned it in this "critical" period.  

answer; the correct answer is (travel horizontally);

because he had a big bear belly