Final answer:
A duplicate copy of the original record should replace a patient's medical record when it is removed from the filing system to maintain record integrity and to prevent loss.
Step-by-step explanation:
When a patient's medical record is removed from the filing system, the correct material to replace it is b) A duplicate copy of the original record. This serves as an out-guide and ensures that anyone looking for the record can track where it has been removed to and by whom.
The duplicate copy typically contains basic information such as the patient's name, the date the file was taken, and the person who removed it. This system is vital for maintaining the integrity of patient information and preventing loss of vital health records.