Where should additional instruments that are seldom used be placed?

Placing additional instruments that are seldom used on the back table is the correct choice because the back table serves as a designated area for instruments and supplies that are not required during the immediate phases of the surgical procedure but may be needed later. This allows the sterile field to remain organized and free from clutter while still ensuring that these instruments are accessible if needed.

The back table is intended for managing items that can be organized away from the immediate surgical area, which helps streamline the procedure and allows the primary instruments in use to be easily accessible on the Mayo stand or the instrument table. This organization is crucial in maintaining an efficient surgical workflow and minimizing any risk of contamination during the operation.