An Administrator Is Decommissioning a Company's Old Accounting System and Will

An administrator is decommissioning a company's old accounting system and will be sending all the hardware to an off-site recycler. Which of the following is the BEST method for the administrator to ensure no company data will be exposed before sending drives to the recycler?

A) Delete both the files and the folders from the hard drives, and then send them to the recycler
B) After logging out and powering down the server, send the drives to the recycler
C) Format all drives using the OS, and then send the drives to the recycler
D) Physically destroy the drives, and then send the drives to the recycler