Cindy Nanson Had a Contract with Bob Greenly for Bob

Cindy Nanson had a contract with Bob Greenly for Bob to repay Cindy $2000 plus interest by July 1986. It is now August 1990 and Cindy has not received any payment. Cindy wishes to file suit to collect the $2000. Bob reminds her that the statute of limitations for contract suits is four years. Cindy's contract with Bob is:

A) unenforceable.
B) void.
C) voidable.
D) all of the above