The fact that Desmond promised to pay Beatrice an extra amount and failed to deliver means that this passage is based on Breach of Contract.
A Breach of Contract occurs when a party breaks a promise that they made to another party. This means that they failed to uphold their side of a contract which then leads to the other party taking losses.
Desmond promised to give Beatrice $250 which means that he entered a unilateral contract. By not fulfilling that promise, he engaged in a breach of contract which Beatrice can take legal action for.
Find out more on unilateral contracts at https://brainly.com/question/15648341
#SPJ1