Answer:
Donna and Carl
Step-by-step explanation:
Owners of the property are Donna and Carl, because Carl has not passed or sold his property to anyone, so Carl has documentation in his name stating that he is the property owner. Similarly, Aaron also had documentation stating that he owned the property, but Aaron sold his property to Donna, so another document was issued stating that Donna is the new owner of the property that was owned by Aaron.
However, Bob, who also had a document stating that he owned the property, died. Bob, before dying, has made it clear that he wants his property to be passed on to Frank after his death, but all documentation left by Bob needs to be reviewed to prove that Frank can inherit his property if proven, new documentation should be made stating that Frank is the owner. Until then only Carl and Donna can claim to be the property owners.