Auser calls the desk and reports that the workstation, when powering up, displays error messages about an invalid system disk or invalid boot disk. when a technician comes to the office, the user mentions that the workstation was working well the day before. the technician checks the workstation and makes sure that the cable is firmly connected between the hard drive and the motherboard. what is another likely cause of the problem?
a. the mbr/gpt is corrupted. b. the boot service fails to start. c. some of the operating system files may be corrupted. d. a recently installed device driver is incompatible with the boot.

Option (A) is the right answer.

Explanation:

According to the scenario, the system is giving error of invalid boot disk when booting, which shows that the system is unable to detect the hard drive used to boot the system.

MBR / GPT is the partition format, which contains the coding which is useful in booting the system. some times the partition files, which contain the coding to boot system corrupts which results in giving an error message of invalid boot disk while booting the system.

Hence the most appropriate answer is option (A).

While the other options are wrong because of the following reasons :

this would start to sound a little like mortal combat