A technician arrives and asks a customer, "Can you describe the problem?" The customer replies, "All email messages that I send have the wrong date. I have restarted the computer several times, but this does not seem to help." What could be the problem?

a. The MBR is corrupted.
b. The CPU voltage is set too low
c. The CMOS battery has failed.
d. The hard drive is beginning to fail.