Family Dollar Stores rejected a $9 billion offer from Dollar General, reaffirming support for a lower bid from Dollar Tree instead. Family Dollar says it is worried Dollar General will be blocked by antitrust hurdles and Jim Cramer says that's a red flag. Cramer says he too believes regulators would indeed block the Dollar General deal. Cramer also says Dollar General could keep Family Dollar in limbo for a long time thereby destroying it whereas Dollar Tree is ready to go. Family Dollar's rejection of Dollar General follows months of growing tensions between the two companies. Cramer says sell Family Dollar.