Andrew Agrees to Paint Rosalene's House for $500

Andrew agrees to paint Rosalene's house for $500. Two days after he starts the job, he decides that $500 isn't enough money. He refuses to finish the job, unless Rosalene agrees to pay him $100 more. What principle applies to this fact situation?

A) The acceptance of additional money to settle a disputed claim is supported by consideration.
B) A past obligation is sufficient consideration for a new promise.
C) Andrew was already obligated to paint the house. He gives no additional consideration in return for Rosalene's promise to pay more money.
D) Rosalene has made a promise in exchange for a forbearance.