Randall Steals a Damaged, Broken Bike That Is Parked, Unlocked

Randall steals a damaged, broken bike that is parked, unlocked, in a dorm bike rack. He repairs, paints, and replac?es parts on the bike un?til it is like new. The original owner, Sabi, then claims it. The bike be?longs to

A) John and Kim in equal measure.
B) John because he made substantial improvements to it.
C) the state under the applicable estray statute.
D) Kim because John stole it.