Explanation:

In computing, "spool" is an acronym used in the context of managing data for peripherals:

- Option 1: Simple peripheral operation on-line - Incorrect, as this does not relate to the true meaning of "spool."

- Option 2: Simple peripheral operation off-line - Incorrect, spool is more about simultaneous processing.

- Option 3: Simultaneous peripheral operation on-line - Correct, as it involves managing data flows to devices such as printers, allowing multiple operations to be processed concurrently and efficiently.

- Option 4: Simultaneous peripheral operation off-line - Incorrect, refers to on-line simultaneous operation, not off-line.

Option 3 (Simultaneous peripheral operation on-line) is the correct choice