Builder enters into a signed written contract with Owner. The contract provides that Builder will build a sun room on Owner's house. The contract price is a flat fee of $11,000 with all the work to be completed by September 1. On August 15, Builder asks to meet with Owner. He tells her that he has more work than he can handle for the month of August. He tells Owner that if she wants the work done by September 1, she will have to pay him an additional $1,000. Owner is very upset about this but doesn't want to delay the construction project past September 1. She agrees and enters into a signed written modification agreement with Builder in which she agrees to pay him an additional $1,000 if the construction is completed by September 1. Which of the following is true:

The second contract at the additional price of $1,000 is unenforceable because it is not supported by consideration

The second contract at the additional price of $1,000 is unenforceable under the doctrine of promissory estoppel.

The second contract is enforceable as an exculpatory clause.

Because it was unforeseen that Builder would demand more money from Owner, under these circumstances, the second contract for the additional $1,000 will be enforced.

Owner was under a pre-existing duty to pay Builder the additional $1,000 in accordance with the modification agreement so she is legally obligated to pay the additional $1,000 to Builder.