Sam Owed Joe $6000 Due January 12, 2017

Sam owed Joe $6000 due January 12, 2017. On January 1st, Joe said he'd take $5000 in full satisfaction of the debt if Sam paid him $5000 on January 5th instead. Sam paid on January 5th. A week later, Joe wants to sue Sam for the $1000 he (Joe) was legally owed. Which of the following is true?

A) Joe would win because his forgiveness of the loan was gratuitous, (i.e., unsupported by consideration) .
B) Joe would win because they cannot change the original deal.
C) Joe would lose because of the doctrine of quantum meruit.
D) Joe would lose because of the rule that past consideration is no consideration.
E) Joe would lose because early repayment constituted consideration to support the new arrangement.