Final answer:
Mary can enforce the contract even though it was not in writing. The receipt serves as evidence of the agreement between Dave and Mary.
Step-by-step explanation:
In this case, Mary can enforce the contract even though it was not in writing. The question asks whether Mary can enforce the contract, and the options given are A) Mary can enforce this contract if the receipt specified that the part payment was for the property in question, B) Mary cannot enforce the agreement because all of the consideration was not paid, C) Mary cannot enforce this contract because the contract was not evidenced in writing, D) Mary cannot enforce this contract because the contract was not in writing, and E) Mary cannot enforce the agreement because she had not paid Dave all of the money.
The correct answer is A) Mary can enforce this contract if the receipt specified that the part payment was for the property in question. Even though the contract was not in writing, the receipt serves as evidence of the agreement between Dave and Mary. The receipt shows that Mary made a part payment for the purchase of the property, indicating a clear intention to enter into a contract.