Answer:
C) the accord or the original obligation.
Explanation:
Based on the scenario being described within the question it can be said that Scott can sue Renee on the accord or the original obligation. This is mainly due to the fact that Renee did not pay the newer arrangement within the three days, and therefore owes Scott the total amount of $25,000 as was agreed by both in the original contract, but since Scott also agreed on the $21,000 he can decide which he would want to sue for.