0 (None): No sharing is allowed. The file can only be accessed by one program at a time.
1 (Read): Multiple programs can read the file simultaneously, but no program can write to it.
2 (Update): Multiple programs can read and write to the file simultaneously, but changes made by one program are not immediately visible to other programs.
3 (Exclusive): Only one program can access the file at a time, and no other program can read or write to it.
b) Share Level:

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