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Which of the following is described in the following statement:
“It is a 512 bytes long boot sector that is the first sector of a default boot drive. It is also known as
Volume Boot Sector, if the boot drive is un-partitioned. “

A.
POST

B.
BIOS

C.
SBR

D.
MBR

Explanation:
The Master Boot Sector (MBR) is a 512-byte long boot sector that is the first sector of a default boot
drive. It is also known as Volume Boot Sector, if the boot drive is un-partitioned. When the MBR is
found, the program is tested and loaded to ensure that the last two bytes are h55AA. The actual
program is only 444 bytes long. The structure of the MBR is as follows:

Answer A is incorrect. Power On Self Test (POST) is a small program stored in a Read Only Memory (ROM)
Basic Input Output System (BIOS) of a computer system starting at address hf000. This program tests
the basic motherboard functions such as power supply, memory, buses, interfaces, etc. and reports
any error with audio beep codes. It also sends diagnostic code to internal port h80 if an error occurs.
enables the operating system to communicate with the computer’s hardware components. The BIOS
software is built-in on a ROM chip, known as Complementary Metal Oxide Semiconductor (CMOS)
chip, on the motherboard.