In how many padlocks are spare padlocks typically sold?

The correct choice indicates that spare padlocks are typically sold in sets of 10, 20, or 40. This range is practical for both commercial and military operations, as it allows organizations to maintain a sufficient inventory of padlocks for various uses, including securing equipment and access points. These quantities facilitate ease of stocking and ensure that enough spare padlocks are available for routine replacements or when increased security measures are needed.

The sets of padlocks are often provided in bulk to accommodate larger-scale requirements, which are common in logistical and operational scenarios. Having a larger number of padlocks on hand helps prevent security lapses due to wear and tear or loss.