James Works for the County Fire Department and Has Not

James works for the county fire department and has not had a raise in three years. When he shows up at the mayor's house to put out a fire, he sees the mayor standing outside. James tells the mayor that he will put out the fire only if the mayor agrees to give him a raise. The mayor agrees. In this scenario, which of the following statements is true?

A) A valid contract exists because all the elements of a valid contract are present.
B) A valid contract does not exist because the value of the consideration for the mayor's promise is inadequate.
C) A valid contract exists because of the past consideration rule.
D) A valid contract does not exist because of the preexisting duty rule.