What is the result of the following command? (Choose 2.)
dd if=/dev/zero of=/dev/hdd bs=512 count=1
A. Overwrites an existing partition table
B. Creates a LVM partition of 512 blocks
C. Backs up the /dev/zero and /dev/hdd files
D. Writes zeros in the first 512 bytes of the first hard disk block
E. Assigns the physical volume zero to the logical volume hdd