Choice "A" is correct. Batch processing updates data periodically (when a batch is processed) while on-line real time processing updates data immediately when transactions are entered.
Choice "b" is incorrect. Data creation may happen at any time for either batch or on-line processing. Those methods are distinguished by the timing of data updating.
Choice "c" is incorrect. Data reading may happen at any time for either batch or on-line processing. Those methods are distinguished by the timing of data updating.
Choice "d" is incorrect. Data deletion or purging may happen at any time for either batch or on-line processing. Those methods are distinguished by the timing of data updating.