Which of the following commands overwrites the bootloader located on /dev/sda without overwriting the partition table or any data following it?
A. dd if=/dev/zero of=/dev/sda bs=512
B. dd if=/dev/zero of=/dev/sda bs=512 count=1
C. dd if=/dev/zero of=/dev/sda bs=440 count=1
D. dd if=/dev/zero of=/dev/sda bs=440