The correct option is
A Careless
The word 'punctilious' refers to showing great attention to detail or correct behaviour.
Option A, foolish indicates lacking good sense or judgement.
Option B, uncommunicative refers to a unwillingness to talk or impart information.
Option C, careless refers to not giving sufficient attention or thought to avoid harm or errors.
Option D, inexperienced refers to having little knowledge or experience of a particular thing.
Thus, according to the meaning, the word 'careless' is the most different in meaning from the word 'punctilious'.