The blood group of a person determines which antigens are present on the surface of their red blood cells and which antibodies are present in their plasma. In this case, ARh$^-$ implies that the person has A antigens on the surface of the red blood cells and does not have the Rh antigen (Rh-negative). Therefore, the person with ARh$^-$ blood can only receive blood from donors whose blood does not contain any antigens that their immune system would recognize as foreign and mount a response against.

For a person with ARh$^-$ blood, suitable donors would have:

1. A antigen (to match the recipient's A antigen) and be Rh-negative.

2. O blood group (which has no A/B antigens) and be Rh-negative.

Let's go through the options:

• BRh$^-$: This blood group has B antigens, which would be recognized as foreign by the immune system of an A blood group recipient, hence it is not suitable.
• ABRh$^-$: This blood group has both A and B antigens, which would also be recognized as foreign due to the presence of the B antigen, making it unsuitable.
• ORh$^-$: This blood group has no A/B antigens, making it a universal donor for all ABO blood types and thus it is suitable for ARh$^-$ recipients.
• ARh$^-$: This blood group matches perfectly with the recipient since it has the same A antigen and is Rh-negative.
• ARh$^+$: This blood group has the A antigen but also has the Rh antigen (Rh-positive). The Rh antigen can trigger an immune response in someone who is Rh-negative, making this option unsuitable.

Therefore, the correct answer is:

Option D: C and D only