Cleo Offers to Sell Her Jack Russell Terrier Puppy to Bridie

Cleo offers to sell her Jack Russell terrier puppy to Bridie for $500 and agrees to keep the offer open until the following Tuesday.The next day she sells the puppy to Tess for $600.In which of the following circumstances will Cleo's actions amount to a breach of contract?

A) Bridie's housemate witnessed Cleo's offer to Bridie and recorded the conversation.
B) Cleo wrote down the promise on a post-it note and gave it to Bridie.
C) Bridie is a close personal friend of Cleo and she lost the opportunity to purchase a puppy from another breeder because she relied on Cleo's promise.
D) Bridie paid Cleo $50 in return for her agreement to keep the offer open.