Answer:
B.
Step-by-step explanation:
Computer manual is the user guide that comes along with the computer set to inform the users about the functions, ways to assemble the parts, and so on.
The user manual consists of guide for the users specially for electronic products such as computers, refrigerators; softwares, and so on. These manuals are written by technical writers, programmers, etc.
In the given scenario the technician needs to refer to computer manual to know the meaning of the lights on the backside of the computer.
So, the correct answer is option B.