The correct answer is: A. a large computer system is available
Batch processing is a type of data processing where transactions are grouped together and processed at a scheduled time. This is in contrast to online processing, where transactions are processed as they occur.
Batch processing is appropriate when there are a large number of transactions to be processed, or when the transactions are complex and require a significant amount of processing time. Batch processing can also be used to process data that is not time-sensitive, such as payroll data or financial statements.
When a large computer system is available, it can be used to process batches of data more efficiently than a small computer system. This is because a large computer system can handle more data at once and can process data more quickly.
Options B, C, and D are incorrect because batch processing is not appropriate when there are only a few transactions to be processed, when the transactions are simple, or when the transactions are time-sensitive.
In conclusion, batch processing is appropriate when there are a large number of transactions to be processed, or when the transactions are complex and require a significant amount of processing time. Batch processing can also be used to process data that is not time-sensitive.