If you fixed the computer, why doesn’t it work?

After completing a normal memory upgrade, you power up the computer and receive an error message on the screen complaining that a boot device isn’t available. The hard drive was working correctly prior to the upgrade. What’s the most likely reason for the error?

A) The new memory modules are faulty

B) The hard drive was damaged during the memory upgrade

C) The hard drive cable was dislodged during the memory upgrade

D) The hard drive controller is incompatible with the new memory modules