In a multi-user database, if two users wish to update the same record at the same time, they are prevented from doing so by

A. jamming

B. password

C. documentation

D. record lock

Please do not use chat terms. Example: avoid using "grt" instead of "great".

You can do it
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  5. HSAM stands for ……….
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  15. Checkpoints are a part of
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