how can the lost GRUB first stage loader be recovered?

A GRUB boot loader installed in the MBR was accidentally overwritten. After booting with a rescue CD-ROM, how can the lost GRUB first stage loader be recovered?

A.
Use dd to restore a previous backup of the MBR

B.
Install LILO since there is no easy way to recover GRUB

C.
Running mformat will create a new MBR and fix GRUB using info from grub.conf

D.
Run grub-install after verifying that grub.conf is correct.

E.
Run fdisk –mbr /dev/had assuming that the boot harddisk is /dev/hda.